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Woodall M, Tarran R, Lee R, Anfishi H, Prins S, Counsell J, Vergani P, Hart S, Baines D. Expression of gain-of-function CFTR in cystic fibrosis airway cells restores epithelial function better than wild-type or codon-optimized CFTR. Mol Ther Methods Clin Dev 2023; 30:593-605. [PMID: 37701179 PMCID: PMC10494266 DOI: 10.1016/j.omtm.2023.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 08/10/2023] [Indexed: 09/14/2023]
Abstract
Class Ia/b cystic fibrosis transmembrane regulator (CFTR) variants cause severe lung disease in 10% of cystic fibrosis (CF) patients and are untreatable with small-molecule pharmaceuticals. Genetic replacement of CFTR offers a cure, but its effectiveness is limited in vivo. We hypothesized that enhancing protein levels (using codon optimization) and/or activity (using gain-of-function variants) of CFTR would more effectively restore function to CF bronchial epithelial cells. Three different variants of the CFTR protein were tested: codon optimized (high codon adaptation index [hCAI]), a gain-of-function (GOF) variant (K978C), and a combination of both (hˆK978C). In human embryonic kidney (HEK293T) cells, initial results showed that hCAI and hˆK978C produced greater than 10-fold more CFTR protein and displayed ∼4-fold greater activity than wild-type (WT) CFTR. However, functionality was profoundly different in CF bronchial epithelial cells. Here, K978C CFTR more potently restored essential epithelial functions (anion transport, airway surface liquid height, and pH) than WT CFTR. hCAI and hˆK978C CFTRs had limited impact because of mislocalization in the cell. These data provide a proof of principle showing that GOF variants may be more effective than codon-optimized forms of CFTR for CF gene therapy. Video abstract
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Affiliation(s)
- Maximillian Woodall
- Institute for Infection and Immunity, St George’s, University of London, Cranmer Terrace, Tooting, London SW17 0RE, UK
| | - Robert Tarran
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7248, USA
| | - Rhianna Lee
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7248, USA
| | - Hafssa Anfishi
- Institute for Infection and Immunity, St George’s, University of London, Cranmer Terrace, Tooting, London SW17 0RE, UK
| | - Stella Prins
- Neuroscience, Physiology, & Pharmacology, Division of Biosciences, University College London, London WC1E 6BT, UK
| | - John Counsell
- Genetics & Genomic Medicine Department, Great Ormond Street Institute of Child Health, London WC1N 1EH, UK
| | - Paola Vergani
- Neuroscience, Physiology, & Pharmacology, Division of Biosciences, University College London, London WC1E 6BT, UK
| | - Stephen Hart
- Genetics & Genomic Medicine Department, Great Ormond Street Institute of Child Health, London WC1N 1EH, UK
| | - Deborah Baines
- Institute for Infection and Immunity, St George’s, University of London, Cranmer Terrace, Tooting, London SW17 0RE, UK
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Song D, Iverson E, Kaler L, Boboltz A, Scull MA, Duncan GA. MUC5B mobilizes and MUC5AC spatially aligns mucociliary transport on human airway epithelium. SCIENCE ADVANCES 2022; 8:eabq5049. [PMID: 36427316 PMCID: PMC9699686 DOI: 10.1126/sciadv.abq5049] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 10/27/2022] [Indexed: 06/16/2023]
Abstract
Secreted mucus is a frontline defense against respiratory infection, enabling the capture and swift removal of infectious or irritating agents from the lungs. Airway mucus is composed of two mucins: mucin 5B (MUC5B) and 5AC (MUC5AC). Together, they form a hydrogel that can be actively transported by cilia along the airway surface. In chronic respiratory diseases, abnormal expression of these mucins is directly implicated in dysfunctional mucus clearance. Yet, the role of each mucin in supporting normal mucus transport remains unclear. Here, we generate human airway epithelial tissue cultures deficient in either MUC5B or MUC5AC to understand their individual contributions to mucus transport. We find that MUC5B and MUC5AC deficiency results in impaired and discoordinated mucociliary transport, respectively, demonstrating the importance of each mucin to airway clearance.
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Affiliation(s)
- Daniel Song
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Ethan Iverson
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Logan Kaler
- Biophysics Program, University of Maryland, College Park, MD 20742, USA
| | - Allison Boboltz
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Margaret A. Scull
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Gregg A. Duncan
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Biophysics Program, University of Maryland, College Park, MD 20742, USA
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Baumann CW, Lindsay A, Sidky SR, Ervasti JM, Warren GL, Lowe DA. Contraction-Induced Loss of Plasmalemmal Electrophysiological Function Is Dependent on the Dystrophin Glycoprotein Complex. Front Physiol 2021; 12:757121. [PMID: 34764884 PMCID: PMC8576390 DOI: 10.3389/fphys.2021.757121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 10/05/2021] [Indexed: 02/03/2023] Open
Abstract
Weakness and atrophy are key features of Duchenne muscular dystrophy (DMD). Dystrophin is one of the many proteins within the dystrophin glycoprotein complex (DGC) that maintains plasmalemmal integrity and cellular homeostasis. The dystrophin-deficient mdx mouse is also predisposed to weakness, particularly when subjected to eccentric (ECC) contractions due to electrophysiological dysfunction of the plasmalemma. Here, we determined if maintenance of plasmalemmal excitability during and after a bout of ECC contractions is dependent on intact and functional DGCs rather than, solely, dystrophin expression. Wild-type (WT) and dystrophic mice (mdx, mL172H and Sgcb-/- mimicking Duchenne, Becker and Limb-girdle Type 2E muscular dystrophies, respectively) with varying levels of dystrophin and DGC functionality performed 50 maximal ECC contractions with simultaneous torque and electromyographic measurements (M-wave root-mean-square, M-wave RMS). ECC contractions caused all mouse lines to lose torque (p<0.001); however, deficits were greater in dystrophic mouse lines compared to WT mice (p<0.001). Loss of ECC torque did not correspond to a reduction in M-wave RMS in WT mice (p=0.080), while deficits in M-wave RMS exceeded 50% in all dystrophic mouse lines (p≤0.007). Moreover, reductions in ECC torque and M-wave RMS were greater in mdx mice compared to mL172H mice (p≤0.042). No differences were observed between mdx and Sgcb-/- mice (p≥0.337). Regression analysis revealed ≥98% of the variance in ECC torque loss could be explained by the variance in M-wave RMS in dystrophic mouse lines (p<0.001) but not within WT mice (R 2=0.211; p=0.155). By comparing mouse lines that had varying amounts and functionality of dystrophin and other DGC proteins, we observed that (1) when all DGCs are intact, plasmalemmal action potential generation and conduction is maintained, (2) deficiency of the DGC protein β-sarcoglycan is as disruptive to plasmalemmal excitability as is dystrophin deficiency and, (3) some functionally intact DGCs are better than none. Our results highlight the significant role of the DGC plays in maintaining plasmalemmal excitability and that a collective synergism (via each DGC protein) is required for this complex to function properly during ECC contractions.
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Affiliation(s)
- Cory W. Baumann
- Department of Biomedical Sciences, Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens, OH, United States
- Divisions of Rehabilitation Science and Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, United States
| | - Angus Lindsay
- Divisions of Rehabilitation Science and Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, United States
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition, Deakin University, Geelong, VIC, Australia
| | - Sylvia R. Sidky
- Divisions of Rehabilitation Science and Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, United States
| | - James M. Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, United States
| | - Gordon L. Warren
- Department of Physical Therapy, Georgia State University, Atlanta, GA, United States
| | - Dawn A. Lowe
- Divisions of Rehabilitation Science and Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, United States
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