1
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Reyne N, Cmielewski P, McCarron A, Delhove J, Parsons D, Donnelley M. Single-Dose Lentiviral Mediated Gene Therapy Recovers CFTR Function in Cystic Fibrosis Knockout Rats. Front Pharmacol 2021; 12:682299. [PMID: 34084147 PMCID: PMC8167067 DOI: 10.3389/fphar.2021.682299] [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: 03/18/2021] [Accepted: 05/04/2021] [Indexed: 01/23/2023] Open
Abstract
Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, resulting in defective ion transport in the airways. Addition of a functioning CFTR gene into affected airway cells has the potential to be an effective treatment for lung disease. The therapeutic efficacy of airway gene transfer can be quantified in animal models by assessing ion transport in the treated nasal epithelium using the nasal potential difference (PD) measurement technique. The nasal PD technique is routinely used in CF mice, however when applied to a recently developed CF rat model those animals did not tolerate the initial nasal PD assessment, therefore the procedure was firstly optimised in rats. This study evaluated the effect of lentiviral (LV)-mediated CFTR airway gene delivery on nasal PD in a CFTR knockout rat model. LV gene vector containing the CFTR gene tagged with a V5 epitope tag (LV-V5-CFTR) was delivered to the nasal epithelium of CF rats, and one week later nasal PD was analysed. This study demonstrated for the first time that LV-V5-CFTR treatment produced a mean correction of 46% towards wild-type chloride response in treated CF rats. Transduced cells were subsequently identifiable using V5 immunohistochemical staining. These findings in the nose validate the use of airway gene therapy for future lung based experiments.
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Affiliation(s)
- Nicole Reyne
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.,Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, SA, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia
| | - Patricia Cmielewski
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.,Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, SA, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia
| | - Alexandra McCarron
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.,Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, SA, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia
| | - Juliette Delhove
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.,Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, SA, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia
| | - David Parsons
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.,Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, SA, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia
| | - Martin Donnelley
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.,Respiratory and Sleep Medicine, Women's and Children's Hospital, North Adelaide, SA, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia
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2
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Leenaars CH, Vries RBD, Reijmer J, Holthaus D, Visser D, Heming A, Elzinga J, Kempkes RW, Beumer W, Punt C, Meijboom FL, Ritskes-Hoitinga M. Animal models for cystic fibrosis: a systematic search and mapping review of the literature. Part 2: nongenetic models. Lab Anim 2021; 55:307-316. [PMID: 33557683 DOI: 10.1177/0023677221990688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Various animal models are available to study cystic fibrosis (CF). These models may help to enhance our understanding of the pathology and contribute to the development of new treatments. We systematically searched all publications on CF animal models. Because of the large number of models retrieved, we split this mapping review into two parts. Previously, we presented the genetic CF animal models. In this paper we present the nongenetic CF animal models. While genetic animal models may, in theory, be preferable for genetic diseases, the phenotype of a genetic model does not automatically resemble human disease. Depending on the research question, other animal models may thus be more informative.We searched Pubmed and Embase and identified 12,303 unique publications (after duplicate removal). All references were screened for inclusion by two independent reviewers. The genetic animal models for CF (from 636 publications) were previously described. The non-genetic CF models (from 189 publications) are described in this paper, grouped by model type: infection-based, pharmacological, administration of human materials, xenografts and other. As before for the genetic models, an overview of basic model characteristics and outcome measures is provided. This CF animal model overview can be the basis for an objective, evidence-based model choice for specific research questions. Besides, it can help to retrieve relevant background literature on outcome measures of interest.
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Affiliation(s)
- Cathalijn Hc Leenaars
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands.,Faculty of Veterinary Medicine, Department of Animals in Science and Society, Utrecht University, The Netherlands.,Institute for Laboratory Animal Science, Hannover Medical School, Germany
| | - Rob Bm de Vries
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands
| | - Joey Reijmer
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands
| | - David Holthaus
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands
| | - Damian Visser
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands
| | - Anna Heming
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands
| | - Janneke Elzinga
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands
| | - Rosalie Wm Kempkes
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands
| | | | - Carine Punt
- ProQR Therapeutics NV,Leiden, the Netherlands; Present position: BunyaVax BV, Lelystad, The Netherlands
| | - Franck Lb Meijboom
- Faculty of Veterinary Medicine, Department of Animals in Science and Society, Utrecht University, The Netherlands
| | - Merel Ritskes-Hoitinga
- SYRCLE, Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, The Netherlands.,Department of Clinical Medicine, Aarhus University, Denmark
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3
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Di W, Clark HA. Optical Nanosensors for in vivo Physiological Chloride Detection for Monitoring Cystic Fibrosis Treatment. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2020; 12:1441-1448. [PMID: 32226484 PMCID: PMC7100910 DOI: 10.1039/c9ay02717c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Personalized approaches for continuous monitoring of chloride levels are potentially valuable for evaluating the efficacy of new treatments of genetic disorders such as cystic fibrosis. In this report, we validated optode-based nanosensors for real-time chloride monitoring in the interstitial fluid of living animals. These nanosensors take advantage of a ratiometric sensing scheme which demonstrates reversible and selective chloride detection in the physiological range. We further investigate how skin pigmentation affects the sensor performance during in vivo fluorescence imaging. We successfully monitored endogenous chloride changes using nanosensors during pharmacological treatment in a cystic fibrosis mouse model. We believe this platform is a valuable tool for chloride detection which could assess the efficacy of new treatments for cystic fibrosis.
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Affiliation(s)
- Wenjun Di
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts 02115, United States
| | - Heather A Clark
- Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, United States
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
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4
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Abstract
Cystic fibrosis is a genetic disease affecting more than 70,000 people worldwide. Caused by a mutation in the CFTR gene, cystic fibrosis can result in difficulty breathing, widespread bacterial infections, edema, malnutrition, pancreatitis, and death. Current drug-based treatments struggle to reach the site of action due to the thick mucus, and only manage symptoms such as blocked airways, lung infections, and limited ability to digest food. Nanotechnology opens up possibilities for improved treatment strategies by focusing on drug penetration through the mucus lining, eliminating resulting bacterial infections, and targeting the underlying genetic cause of the disease. In this review, we present recent nanoparticle developments for cystic fibrosis, challenges in nanomedicine therapeutics, and future research directions in gene editing and nonviral vectors for gene delivery.
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Affiliation(s)
- Victor Ong
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Vincent Mei
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Lin Cao
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Kiana Lee
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Eun Ji Chung
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- 2 Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, USA
- 3 Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- 4 Division of Vascular Surgery and Endovascular Repair, Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- 5 Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
- 6 Department of Stem Cell Biology and Regenerative Medicine, University of Southern California, Los Angeles, CA, USA
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5
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Carlon MS, Vidović D, Birket S. Roadmap for an early gene therapy for cystic fibrosis airway disease. Prenat Diagn 2017; 37:1181-1190. [DOI: 10.1002/pd.5164] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/12/2017] [Accepted: 09/28/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Marianne S. Carlon
- Molecular Virology and Gene Therapy; Department of Pharmaceutical and Pharmacological Sciences; KU Leuven Flanders Belgium
| | - Dragana Vidović
- Molecular Virology and Gene Therapy; Department of Pharmaceutical and Pharmacological Sciences; KU Leuven Flanders Belgium
- Current affiliation: Cellular Protein Chemistry, Faculty of Science; Utrecht University; The Netherlands
| | - Susan Birket
- Department of Medicine; University of Alabama at Birmingham; Birmingham AL USA
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6
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Sondhi D, Stiles KM, De BP, Crystal RG. Genetic Modification of the Lung Directed Toward Treatment of Human Disease. Hum Gene Ther 2017; 28:3-84. [PMID: 27927014 DOI: 10.1089/hum.2016.152] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Genetic modification therapy is a promising therapeutic strategy for many diseases of the lung intractable to other treatments. Lung gene therapy has been the subject of numerous preclinical animal experiments and human clinical trials, for targets including genetic diseases such as cystic fibrosis and α1-antitrypsin deficiency, complex disorders such as asthma, allergy, and lung cancer, infections such as respiratory syncytial virus (RSV) and Pseudomonas, as well as pulmonary arterial hypertension, transplant rejection, and lung injury. A variety of viral and non-viral vectors have been employed to overcome the many physical barriers to gene transfer imposed by lung anatomy and natural defenses. Beyond the treatment of lung diseases, the lung has the potential to be used as a metabolic factory for generating proteins for delivery to the circulation for treatment of systemic diseases. Although much has been learned through a myriad of experiments about the development of genetic modification of the lung, more work is still needed to improve the delivery vehicles and to overcome challenges such as entry barriers, persistent expression, specific cell targeting, and circumventing host anti-vector responses.
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Affiliation(s)
- Dolan Sondhi
- Department of Genetic Medicine, Weill Cornell Medical College , New York, New York
| | - Katie M Stiles
- Department of Genetic Medicine, Weill Cornell Medical College , New York, New York
| | - Bishnu P De
- Department of Genetic Medicine, Weill Cornell Medical College , New York, New York
| | - Ronald G Crystal
- Department of Genetic Medicine, Weill Cornell Medical College , New York, New York
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7
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Alton EWFW, Beekman JM, Boyd AC, Brand J, Carlon MS, Connolly MM, Chan M, Conlon S, Davidson HE, Davies JC, Davies LA, Dekkers JF, Doherty A, Gea-Sorli S, Gill DR, Griesenbach U, Hasegawa M, Higgins TE, Hironaka T, Hyndman L, McLachlan G, Inoue M, Hyde SC, Innes JA, Maher TM, Moran C, Meng C, Paul-Smith MC, Pringle IA, Pytel KM, Rodriguez-Martinez A, Schmidt AC, Stevenson BJ, Sumner-Jones SG, Toshner R, Tsugumine S, Wasowicz MW, Zhu J. Preparation for a first-in-man lentivirus trial in patients with cystic fibrosis. Thorax 2016; 72:137-147. [PMID: 27852956 PMCID: PMC5284333 DOI: 10.1136/thoraxjnl-2016-208406] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 06/21/2016] [Accepted: 06/28/2016] [Indexed: 01/03/2023]
Abstract
We have recently shown that non-viral gene therapy can stabilise the decline of lung function in patients with cystic fibrosis (CF). However, the effect was modest, and more potent gene transfer agents are still required. Fuson protein (F)/Hemagglutinin/Neuraminidase protein (HN)-pseudotyped lentiviral vectors are more efficient for lung gene transfer than non-viral vectors in preclinical models. In preparation for a first-in-man CF trial using the lentiviral vector, we have undertaken key translational preclinical studies. Regulatory-compliant vectors carrying a range of promoter/enhancer elements were assessed in mice and human air–liquid interface (ALI) cultures to select the lead candidate; cystic fibrosis transmembrane conductance receptor (CFTR) expression and function were assessed in CF models using this lead candidate vector. Toxicity was assessed and ‘benchmarked’ against the leading non-viral formulation recently used in a Phase IIb clinical trial. Integration site profiles were mapped and transduction efficiency determined to inform clinical trial dose-ranging. The impact of pre-existing and acquired immunity against the vector and vector stability in several clinically relevant delivery devices was assessed. A hybrid promoter hybrid cytosine guanine dinucleotide (CpG)- free CMV enhancer/elongation factor 1 alpha promoter (hCEF) consisting of the elongation factor 1α promoter and the cytomegalovirus enhancer was most efficacious in both murine lungs and human ALI cultures (both at least 2-log orders above background). The efficacy (at least 14% of airway cells transduced), toxicity and integration site profile supports further progression towards clinical trial and pre-existing and acquired immune responses do not interfere with vector efficacy. The lead rSIV.F/HN candidate expresses functional CFTR and the vector retains 90–100% transduction efficiency in clinically relevant delivery devices. The data support the progression of the F/HN-pseudotyped lentiviral vector into a first-in-man CF trial in 2017.
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Affiliation(s)
- Eric W F W Alton
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Jeffery M Beekman
- Department of Pediatric Pulmonology, Laboratory of Translational Immunology, Wilhelmina Children's Hospital, University Medical Centre, Utrecht, The Netherlands
| | - A Christopher Boyd
- Centre for Genomic and Experimental Medicine, IGMM, University of Edinburgh, Edinburgh, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - June Brand
- Centre for Genomic and Experimental Medicine, IGMM, University of Edinburgh, Edinburgh, UK.,Lung Pathology Unit, Department of Airway Disease Infection, NHLI, Imperial College London, London, UK
| | - Marianne S Carlon
- Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Brussels, Belgium
| | - Mary M Connolly
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Gene Medicine Research Group, NDCLS, John Radcliffe Hospital, Oxford, UK
| | - Mario Chan
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Sinead Conlon
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Heather E Davidson
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Centre for Genomic and Experimental Medicine, IGMM, University of Edinburgh, Edinburgh, UK
| | - Jane C Davies
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Lee A Davies
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Gene Medicine Research Group, NDCLS, John Radcliffe Hospital, Oxford, UK
| | - Johanna F Dekkers
- Department of Pediatric Pulmonology, Laboratory of Translational Immunology, Wilhelmina Children's Hospital, University Medical Centre, Utrecht, The Netherlands
| | - Ann Doherty
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Centre for Genomic and Experimental Medicine, IGMM, University of Edinburgh, Edinburgh, UK
| | - Sabrina Gea-Sorli
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Deborah R Gill
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Gene Medicine Research Group, NDCLS, John Radcliffe Hospital, Oxford, UK
| | - Uta Griesenbach
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | | | - Tracy E Higgins
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | | | - Laura Hyndman
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Centre for Genomic and Experimental Medicine, IGMM, University of Edinburgh, Edinburgh, UK
| | - Gerry McLachlan
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Roslin Institute & R(D)SVS, University of Edinburgh, Midlothian, UK
| | - Makoto Inoue
- ID Pharme Co. Ltd. (DNAVEC Center), Tsukuba, Japan
| | - Stephen C Hyde
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Gene Medicine Research Group, NDCLS, John Radcliffe Hospital, Oxford, UK
| | - J Alastair Innes
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Centre for Genomic and Experimental Medicine, IGMM, University of Edinburgh, Edinburgh, UK
| | - Toby M Maher
- Fibrosis Research Group, Inflammation, Repair & Development Section, National Heart and Lung Institute, Sir Alexander Fleming Building, Imperial College, London, UK
| | - Caroline Moran
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Cuixiang Meng
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Michael C Paul-Smith
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Ian A Pringle
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Gene Medicine Research Group, NDCLS, John Radcliffe Hospital, Oxford, UK
| | - Kamila M Pytel
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Andrea Rodriguez-Martinez
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | | | - Barbara J Stevenson
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Centre for Genomic and Experimental Medicine, IGMM, University of Edinburgh, Edinburgh, UK
| | - Stephanie G Sumner-Jones
- UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK.,Gene Medicine Research Group, NDCLS, John Radcliffe Hospital, Oxford, UK
| | - Richard Toshner
- Fibrosis Research Group, Inflammation, Repair & Development Section, National Heart and Lung Institute, Sir Alexander Fleming Building, Imperial College, London, UK
| | | | - Marguerite W Wasowicz
- Department of Gene Therapy, National Heart and Lung Institute, Imperial College London, London, UK.,UK Cystic Fibrosis Gene Therapy Consortium, Oxford, UK
| | - Jie Zhu
- Lung Pathology Unit, Department of Airway Disease Infection, NHLI, Imperial College London, London, UK
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8
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da Cunha MF, Simonin J, Sassi A, Freund R, Hatton A, Cottart CH, Elganfoud N, Zoubairi R, Dragu C, Jais JP, Hinzpeter A, Edelman A, Sermet-Gaudelus I. Analysis of nasal potential in murine cystic fibrosis models. Int J Biochem Cell Biol 2016; 80:87-97. [PMID: 27717840 DOI: 10.1016/j.biocel.2016.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 12/27/2022]
Abstract
The nasal epithelium of the mouse closely mimics the bioelectrical phenotype of the human airways. Ion transport across the nasal epithelium induces a nasal transepithelial potential difference. Its measurement by a relatively non-invasive method adapted from humans allows in vivo longitudinal measurements of CFTR-dependent ionic transport in the murine nasal mucosa. This test offers a useful tool to assess CFTR function in preclinical studies for novel therapeutics modulating CFTR activity. Here we extensively review work done to assess transepithelial transport in the murine respiratory epithelium in the basal state and after administration of CFTR modulators. Factors of variability and discriminative threshold between the CF and the WT mice for different readouts are discussed.
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Affiliation(s)
- Mélanie Faria da Cunha
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
| | - Juliette Simonin
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
| | - Ali Sassi
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
| | - Romain Freund
- Unité de Biostatistiques, Hôpital Necker Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Aurélie Hatton
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
| | - Charles-Henry Cottart
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
| | - Nadia Elganfoud
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
| | - Rachid Zoubairi
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
| | - Corina Dragu
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
| | - Jean Philippe Jais
- Unité de Biostatistiques, Hôpital Necker Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Alexandre Hinzpeter
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
| | - Aleksander Edelman
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Sorbonne, Paris, France
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9
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Alton EWFW, Boyd AC, Davies JC, Gill DR, Griesenbach U, Harrison PT, Henig N, Higgins T, Hyde SC, Innes JA, Korman MSD. Genetic medicines for CF: Hype versus reality. Pediatr Pulmonol 2016; 51:S5-S17. [PMID: 27662105 DOI: 10.1002/ppul.23543] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 12/19/2022]
Abstract
Since identification of the CFTR gene over 25 years ago, gene therapy for cystic fibrosis (CF) has been actively developed. More recently gene therapy has been joined by other forms of "genetic medicines" including mRNA delivery, as well as genome editing and mRNA repair-based strategies. Proof-of-concept that gene therapy can stabilize the progression of CF lung disease has recently been established in a Phase IIb trial. An early phase study to assess the safety and explore efficacy of CFTR mRNA repair is ongoing, while mRNA delivery and genome editing-based strategies are currently at the pre-clinical phase of development. This review has been written jointly by some of those involved in the various CF "genetic medicine" fields and will summarize the current state-of-the-art, as well as discuss future developments. Where applicable, it highlights common problems faced by each of the strategies, and also tries to highlight where a specific strategy may have an advantage on the pathway to clinical translation. We hope that this review will contribute to the ongoing discussion about the hype versus reality of genetic medicine-based treatment approaches in CF. Pediatr Pulmonol. 2016;51:S5-S17. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Eric W F W Alton
- UK Cystic Fibrosis Gene Therapy Consortium, Edinburgh, Oxford, London
| | | | - Jane C Davies
- UK Cystic Fibrosis Gene Therapy Consortium, Edinburgh, Oxford, London
| | - Deborah R Gill
- UK Cystic Fibrosis Gene Therapy Consortium, Edinburgh, Oxford, London
| | - Uta Griesenbach
- UK Cystic Fibrosis Gene Therapy Consortium, Edinburgh, Oxford, London.
| | - Patrick T Harrison
- Department of Physiology and BioSciences Institute, University College Cork, Cork, Ireland
| | | | - Tracy Higgins
- UK Cystic Fibrosis Gene Therapy Consortium, Edinburgh, Oxford, London
| | - Stephen C Hyde
- UK Cystic Fibrosis Gene Therapy Consortium, Edinburgh, Oxford, London
| | - J Alastair Innes
- UK Cystic Fibrosis Gene Therapy Consortium, Edinburgh, Oxford, London
| | - Michael S D Korman
- Department of Pediatrics I - Pediatric Infectiology and Immunology - Translational Genomics and Gene Therapy, University of Tübingen, Tübingen, Germany
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10
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Paul-Smith MC, Bell RV, Alton WE, Alton EW, Griesenbach U. Gene therapy for cystic fibrosis: recent progress and current aims. Expert Opin Orphan Drugs 2016. [DOI: 10.1080/21678707.2016.1180974] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Michael C. Paul-Smith
- Department of Gene Therapy and the UK Cystic Fibrosis Gene Therapy Consortium, Imperial College, London, UK
| | - Robyn V. Bell
- Department of Gene Therapy and the UK Cystic Fibrosis Gene Therapy Consortium, Imperial College, London, UK
| | - William E. Alton
- Department of Gene Therapy and the UK Cystic Fibrosis Gene Therapy Consortium, Imperial College, London, UK
| | - Eric W.F.W. Alton
- Department of Gene Therapy and the UK Cystic Fibrosis Gene Therapy Consortium, Imperial College, London, UK
| | - Uta Griesenbach
- Department of Gene Therapy and the UK Cystic Fibrosis Gene Therapy Consortium, Imperial College, London, UK
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11
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Characterization of nasal potential difference in cftr knockout and F508del-CFTR mice. PLoS One 2013; 8:e57317. [PMID: 23505426 PMCID: PMC3591431 DOI: 10.1371/journal.pone.0057317] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 01/21/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Treatments designed to correct cystic fibrosis transmembrane conductance regulator (CFTR) defects must first be evaluated in preclinical experiments in the mouse model of cystic fibrosis (CF). Mice nasal mucosa mimics the bioelectric defect seen in humans. The use of nasal potential difference (V(TE)) to assess ionic transport is a powerful test evaluating the restoration of CFTR function. Nasal V(TE) in CF mice must be well characterized for correct interpretation. METHODS We performed V(TE) measurements in large-scale studies of two mouse models of CF--B6;129 cftr knockout and FVB F508del-CFTR--and their respective wild-type (WT) littermates. We assessed the repeatability of the test for cftr knockout mice and defined cutoff points distinguishing between WT and F508del-CFTR mice. RESULTS We determined the typical V(TE) values for CF and WT mice and demonstrated the existence of residual CFTR activity in F508del-CFTR mice. We characterized intra-animal variability in B6;129 mice and defined the cutoff points for F508del-CFTR chloride secretion rescue. Hyperpolarization of more than -2.15 mV after perfusion with a low-concentration Cl(-) solution was considered to indicate a normal response. CONCLUSIONS These data will make it possible to interpret changes in nasal V(TE) in mouse models of CF, in future preclinical studies.
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12
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Donnelley M, Morgan KS, Siu KKW, Parsons DW. Variability of in vivo fluid dose distribution in mouse airways is visualized by high-speed synchrotron X-ray imaging. J Aerosol Med Pulm Drug Deliv 2013; 26:307-16. [PMID: 23298238 DOI: 10.1089/jamp.2012.1007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The manner in which fluid instillations into mouse nose and lung distribute through the airways is poorly understood. Many agents are delivered in this way for testing as therapeutics, or as challenges designed to establish infections or create systemic drug delivery effects. These agents are delivered into mouse airways with little knowledge of the manner in which doses move through the airways, how long they reside in each region, and where the instilled materials eventually reach. METHODS Synchrotron phase-contrast X-ray imaging (PCXI) was used to elucidate the primary controlling characteristics of mouse airway fluid dosing. High-speed image acquisition was used to track the movement of a range of bolus doses of an iodine-based contrast fluid through the nose (n=15) and lungs (n=10) of live anesthetized mice. For the lung studies, the mice were ventilated and paralyzed to control animal movement. Post-experiment image processing was used to visualize the fluid movement. RESULTS The maximum dose that could be retained in only the anterior nose was ∼7.5 μL (20 g mouse), and a range of dynamic dose behaviors was documented after delivery. In the lung, the use of mechanical ventilation in combination with a paralytic agent prevented confounding artifactual movement, improving visualization of fluid progression through the airways. In the lung, optimized image analysis using the high image capture rate revealed the presence of respiratory pauses that could not be visualized at slower acquisition rates. The variability in the outcome of identical dose deliveries in different animals indicates that uniform lung distribution cannot be expected to occur with tracheal fluid delivery. CONCLUSIONS With adequate imaging rate and fluid dose parameters, this study shows the utility of synchrotron PCXI for determining the post-delivery behavior and fate of fluid doses such as those used in in vivo gene transfer or pharmaceutical studies.
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Affiliation(s)
- Martin Donnelley
- 1 Respiratory and Sleep Medicine, Women's and Children's Health Network , Adelaide, Australia
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Burney TJ, Davies JC. Gene therapy for the treatment of cystic fibrosis. APPLICATION OF CLINICAL GENETICS 2012; 5:29-36. [PMID: 23776378 PMCID: PMC3681190 DOI: 10.2147/tacg.s8873] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Gene therapy is being developed as a novel treatment for cystic fibrosis (CF), a condition that has hitherto been widely-researched yet for which no treatment exists that halts the progression of lung disease. Gene therapy involves the transfer of correct copies of cystic fibrosis transmembrane conductance regulator (CFTR) DNA to the epithelial cells in the airways. The cloning of the CFTR gene in 1989 led to proof-of-principle studies of CFTR gene transfer in vitro and in animal models. The earliest clinical trials in CF patients were conducted in 1993 and used viral and non-viral gene transfer agents in both the nasal and bronchial airway epithelium. To date, studies have focused largely on molecular or bioelectric (chloride secretion) outcome measures, many demonstrating evidence of CFTR expression, but few have attempted to achieve clinical efficacy. As CF is a lifelong disease, turnover of the airway epithelium necessitates repeat administration. To date, this has been difficult to achieve with viral gene transfer agents due to host recognition leading to loss of expression. The UK Cystic Fibrosis Gene Therapy Consortium (Imperial College London, University of Edinburgh and University of Oxford) is currently working on a large and ambitious program to establish the clinical benefits of CF gene therapy. Wave 1, which has reached the clinic, uses a non-viral vector. A single-dose safety trial is nearing completion and a multi-dose clinical trial is shortly due to start; this will be powered for clinically-relevant changes. Wave 2, more futuristically, will look at the potential of lentiviruses, which have long-lasting expression. This review will summarize the current status of translational research in CF gene therapy.
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Affiliation(s)
- Tabinda J Burney
- Department of Gene Therapy, Imperial College London ; UK CF Gene Therapy Consortium London
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Hodges CA, Grady BR, Mishra K, Cotton CU, Drumm ML. Cystic fibrosis growth retardation is not correlated with loss of Cftr in the intestinal epithelium. Am J Physiol Gastrointest Liver Physiol 2011; 301:G528-36. [PMID: 21659619 PMCID: PMC3174541 DOI: 10.1152/ajpgi.00052.2011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Maldigestion due to exocrine pancreatic insufficiency leads to intestinal malabsorption and consequent malnutrition, a mechanism proposed to cause growth retardation associated with cystic fibrosis (CF). However, although enzyme replacement therapy combined with increased caloric intake improves weight gain, the effect on stature is not significant, suggesting that growth retardation has a more complex etiology. Mouse models of CF support this, since these animals do not experience exocrine pancreatic insufficiency yet are growth impaired. Cftr absence from the intestinal epithelium has been suggested as a primary source of growth retardation in CF mice, a concept we directly tested by generating mouse models with Cftr selectively inactivated or restored in intestinal epithelium. The relationship between growth and functional characteristics of the intestines, including transepithelial electrophysiology, incidence of intestinal obstruction, and histopathology, were assessed. Absence of Cftr exclusively from intestinal epithelium resulted in loss of cAMP-stimulated short-circuit current, goblet cell hyperplasia, and occurrence of intestinal obstructions but only slight and transient impaired growth. In contrast, specifically restoring Cftr to the intestinal epithelium resulted in restoration of ion transport and completely protected against obstruction and histopathological anomalies, but growth was indistinguishable from CF mice. These results indicate that absence of Cftr in the intestinal epithelium is an important contributor to the intestinal obstruction phenotype in CF but does not correlate with the observed growth reduction in CF.
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Affiliation(s)
| | | | | | | | - Mitchell L. Drumm
- Departments of 1Pediatrics, ,3Genetics, Case Western Reserve University School of Medicine, Cleveland, Ohio
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Donnelley M, Siu KKW, Jamison RA, Parsons DW. Synchrotron phase-contrast X-ray imaging reveals fluid dosing dynamics for gene transfer into mouse airways. Gene Ther 2011; 19:8-14. [PMID: 21654825 DOI: 10.1038/gt.2011.80] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although airway gene transfer research in mouse models relies on bolus fluid dosing into the nose or trachea, the dynamics and immediate fate of delivered gene transfer agents are poorly understood. In particular, this is because there are no in vivo methods able to accurately visualize the movement of fluid in small airways of intact animals. Using synchrotron phase-contrast X-ray imaging, we show that the fate of surrogate fluid doses delivered into live mouse airways can now be accurately and non-invasively monitored with high spatial and temporal resolution. This new imaging approach can help explain the non-homogenous distributions of gene expression observed in nasal airway gene transfer studies, suggests that substantial dose losses may occur at deliver into mouse trachea via immediate retrograde fluid motion and shows the influence of the speed of bolus delivery on the relative targeting of conducting and deeper lung airways. These findings provide insight into some of the factors that can influence gene expression in vivo, and this method provides a new approach to documenting and analyzing dose delivery in small-animal models.
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Affiliation(s)
- M Donnelley
- Department of Respiratory and Sleep Medicine, Women's and Children's Hospital, Adelaide, Australia.
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16
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Griesenbach U, Sumner-Jones SG, Holder E, Munkonge FM, Wodehouse T, Smith SN, Wasowicz MY, Pringle I, Casamayor I, Chan M, Coles R, Cornish N, Dewar A, Doherty A, Farley R, Green AM, Jones BL, Larsen MDB, Lawton AE, Manvell M, Painter H, Singh C, Somerton L, Stevenson B, Varathalingam A, Siegel C, Scheule RK, Cheng SH, Davies JC, Porteous DJ, Gill DR, Boyd AC, Hyde SC, Alton EWFW. Limitations of the Murine Nose in the Development of Nonviral Airway Gene Transfer. Am J Respir Cell Mol Biol 2010; 43:46-54. [DOI: 10.1165/rcmb.2009-0075oc] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Cmielewski P, Anson DS, Parsons DW. Lysophosphatidylcholine as an adjuvant for lentiviral vector mediated gene transfer to airway epithelium: effect of acyl chain length. Respir Res 2010; 11:84. [PMID: 20569421 PMCID: PMC2905357 DOI: 10.1186/1465-9921-11-84] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 06/23/2010] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Poor gene transfer efficiency has been a major problem in developing an effective gene therapy for cystic fibrosis (CF) airway disease. Lysophosphatidylcholine (LPC), a natural airway surfactant, can enhance viral gene transfer in animal models. We examined the electrophysiological and physical effect of airway pre-treatment with variants of LPC on lentiviral (LV) vector gene transfer efficiency in murine nasal airways in vivo. METHODS Gene transfer was assessed after 1 week following nasal instillations of a VSV-G pseudotype LV vector pre-treated with a low and high dose of LPC variants. The electrophysiological effects of a range of LPC variants were assessed by nasal transepithelial potential difference measurements (TPD) to determine tight junction permeability. Any physical changes to the epithelium from administration of the LPC variants were noted by histological methods in airway tissue harvested after 1 hour. RESULTS Gene transduction was significantly greater compared to control (PBS) for our standard LPC (palmitoyl/stearoyl mixture) treatment and for the majority of the other LPC variants with longer acyl chain lengths. The LPC variant heptadecanoyl also produced significantly greater LV gene transfer compared to our standard LPC mixture. LV gene transfer and the transepithelial depolarization produced by the 0.1% LPC variants at 1 hour were strongly correlated (r2 = 0.94), but at the 1% concentration the correlation was less strong (r2 = 0.59). LPC variants that displayed minor to moderate levels of disruption to the airway epithelium were clearly associated with higher LV gene transfer. CONCLUSIONS These findings show the LPC variants effect on airway barrier function and their correlation to the effectiveness of gene expression. The enhanced expression produced by a number of LPC variants should provide new options for preclinical development of efficient airway gene transfer techniques.
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Affiliation(s)
- Patricia Cmielewski
- Dept of Respiratory and Sleep Medicine, Women's and Children's Hospital, 72 King William Rd, North Adelaide, SA 5006, Australia.
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18
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The use of carboxymethylcellulose gel to increase non-viral gene transfer in mouse airways. Biomaterials 2009; 31:2665-72. [PMID: 20022367 DOI: 10.1016/j.biomaterials.2009.12.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 12/01/2009] [Indexed: 11/21/2022]
Abstract
We have assessed whether viscoelastic gels known to inhibit mucociliary clearance can increase lipid-mediated gene transfer. Methylcellulose or carboxymethylcellulose (0.25-1.5%) was mixed with complexes of the cationic lipid GL67A and plasmids encoding luciferase and perfused onto the nasal epithelium of mice. Survival after perfusion with 1% CMC or 1% MC was 90 and 100%, respectively. In contrast 1.5% CMC was uniformly lethal likely due to the viscous solution blocking the airways. Perfusion with 0.5% CMC containing lipid/DNA complexes reproducibly increased gene expression by approximately 3-fold (n=16, p<0.05). Given this benefit, likely related to increased duration of contact, we also assessed the effect of prolonging contact time of the liposome/DNA complexes by delivering our standard 80 microg DNA dose over either approximately 22 or 60 min of perfusion. This independently increased gene transfer by 6-fold (n=8, p<0.05) and could be further enhanced by the addition of 0.5% CMC, leading to an overall 25-fold enhancement (n=8, p<0.001) in gene expression. As a result of these interventions CFTR transgene mRNA transgene levels were increased several logs above background. Interestingly, this did not lead to correction of the ion transport defects in the nasal epithelium of cystic fibrosis mice nor for immunohistochemical quantification of CFTR expression. To assess if 0.5% CMC also increased gene transfer in the mouse lung, we used whole body nebulisation chambers. CMC was nebulised for 1h immediately before, or simultaneously with GL67A/pCIKLux. The former did not increase gene transfer, whereas co-administration significantly increased gene transfer by 4-fold (p<0.0001, n=18). This study suggests that contact time of non-viral gene transfer agents is a key factor for gene delivery, and suggests two methods which may be translatable for use in man.
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Stocker AG, Kremer KL, Koldej R, Miller DS, Anson DS, Parsons DW. Single-dose lentiviral gene transfer for lifetime airway gene expression. J Gene Med 2009; 11:861-7. [PMID: 19634193 DOI: 10.1002/jgm.1368] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Cystic fibrosis (CF) is caused by a defect in cystic fibrosis transmembrane conductance regulator (CFTR) activity, often resulting in an incurable airway disease. Gene therapy into the conducting airway epithelium is a potential cure for CF; however, most gene vectors do not result in long-lived expression, and require re-dosing. Perversely, intrinsic host immune responses can then block renewed gene transfer. METHODS To investigate whether persistent gene expression could be achieved after a single dosing event, thus avoiding the issue of blocking host responses, we used a gene transfer protocol that combined an airway pretreatment using lysophosphatidylcholine with a human immunodeficiency virus type-1 (vesicular stomatitis virus G pseudotype) derived lentiviral vector to test whether an integrating vector could produce gene expression able to last for a substantial part of the lifetime of the laboratory mouse. RESULTS We found that a single dose of LV-LacZ produced immediate as well as lifetime mouse airway expression, confirming our hypothesis that use of an integrating vector extends transgene expression. Importantly, LV-CFTR dosing achieved at least 12 months of CFTR expression, representing partial functional correction of the CFTR defect in CF-null mice. CONCLUSIONS These findings validate the potential of this methodology for developing a gene transfer treatment for CF airway disease.
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Affiliation(s)
- Alice G Stocker
- Department of Respiratory and Sleep Medicine, Women's & Children's Hospital, Children, Youth & Women's Health Service, North Adelaide 5006, Australia
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Grubb BR, Rogers TD, Boucher RC, Ostrowski LE. Ion transport across CF and normal murine olfactory and ciliated epithelium. Am J Physiol Cell Physiol 2009; 296:C1301-9. [PMID: 19321738 DOI: 10.1152/ajpcell.00578.2008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The nasal epithelium of the cystic fibrosis (CF) mouse has been used extensively in CF research because it exhibits ion transport defects similar to those of human CF airways. This tissue is composed of approximately 50% olfactory (OE) and approximately 50% ciliated epithelium (CE), and on the basis of previous observations, we hypothesized that a significant fraction of the bioelectric signals from murine nasal tissue may arise from OE rather than CE, while CE is the target tissue for CF gene therapy. We compared the bioelectric properties of isolated OE from the nasal cavity and CE from the nasopharynx in Ussing chamber studies. Hyperabsorption of Na(+) [amiloride response; CF vs. wild type (WT)] was approximately 7.5-fold greater in the OE compared with the CE. The forskolin response in native tissues did not reliably distinguish genotypes, likely due to a cyclic nucleotide-gated cation conductance in OE and a calcium-mediated Cl(-) conductance in CE. By potential difference assay, hyperabsorption of Na(+) (CF vs. WT) and the difference in response to apical 0 Cl(-) buffer (CF vs. WT) were approximately 2-fold greater in the nasal cavity compared with the nasopharynx. Our studies demonstrate that in the CF mouse, both the hyperabsorption of Na(+) and the Cl(-) transport defect are of larger magnitude in the OE than in the CE. Thus, while the murine CF nasal epithelium is a valuable model for CF studies, the bioelectrics are likely dominated by the signals from the OE, and assays of the nasopharynx may be more specific for studying the ciliated epithelium.
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Affiliation(s)
- B R Grubb
- Cystic Fibrosis/Pulmonary Research and Treatment Center, 7011 Thurston-Bowles Bldg., CB 7248, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolia 27599-7248, USA.
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