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Gentzsch M, Baker B, Cholon DM, Kam CW, McKinzie CJ, Despotes KA, Boyles SE, Quinney NL, Esther CR, Ribeiro CM. Cystic fibrosis airway inflammation enables elexacaftor/tezacaftor/ivacaftor-mediated rescue of N1303K CFTR mutation. ERJ Open Res 2024; 10:00746-2023. [PMID: 38226069 PMCID: PMC10789252 DOI: 10.1183/23120541.00746-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 10/18/2023] [Indexed: 01/17/2024] Open
Abstract
Rescue of N1303K CFTR by highly effective modulator therapy (HEMT) is enabled by CF airway inflammation. These findings suggest that evaluation of HEMT for rare CFTR mutations must be performed under inflammatory conditions relevant to CF airways. https://bit.ly/3tTcoJE.
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Affiliation(s)
- Martina Gentzsch
- Marsico Lung Institute and Cystic Fibrosis Research Center, The University of North Carolina, Chapel Hill, NC, USA
- Department of Pediatrics, The University of North Carolina, Chapel Hill, NC, USA
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC, USA
- Joint first authors
| | - Brooke Baker
- Department of Pharmacy, Duke University Medical Center, Durham, NC, USA
- Joint first authors
| | - Deborah M. Cholon
- Marsico Lung Institute and Cystic Fibrosis Research Center, The University of North Carolina, Chapel Hill, NC, USA
| | - Charissa W. Kam
- Department of Pharmacy, University of North Carolina Medical Center, Chapel Hill, NC, USA
| | - Cameron J. McKinzie
- Department of Pharmacy, University of North Carolina Medical Center, Chapel Hill, NC, USA
| | | | - Susan E. Boyles
- Marsico Lung Institute and Cystic Fibrosis Research Center, The University of North Carolina, Chapel Hill, NC, USA
| | - Nancy L. Quinney
- Marsico Lung Institute and Cystic Fibrosis Research Center, The University of North Carolina, Chapel Hill, NC, USA
| | - Charles R. Esther
- Marsico Lung Institute and Cystic Fibrosis Research Center, The University of North Carolina, Chapel Hill, NC, USA
- Department of Pediatrics, The University of North Carolina, Chapel Hill, NC, USA
- Joint senior authors
| | - Carla M.P. Ribeiro
- Marsico Lung Institute and Cystic Fibrosis Research Center, The University of North Carolina, Chapel Hill, NC, USA
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC, USA
- Department of Medicine, The University of North Carolina, Chapel Hill, NC, USA
- Joint senior authors
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2
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Cholon DM, Greenwald MA, Higgs MG, Quinney NL, Boyles SE, Meinig SL, Minges JT, Chaubal A, Tarran R, Ribeiro CMP, Wolfgang MC, Gentzsch M. A Novel Co-Culture Model Reveals Enhanced CFTR Rescue in Primary Cystic Fibrosis Airway Epithelial Cultures with Persistent Pseudomonas aeruginosa Infection. Cells 2023; 12:2618. [PMID: 37998353 PMCID: PMC10670530 DOI: 10.3390/cells12222618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 10/31/2023] [Accepted: 11/06/2023] [Indexed: 11/25/2023] Open
Abstract
People with cystic fibrosis (pwCF) suffer from chronic and recurring bacterial lung infections that begin very early in life and contribute to progressive lung failure. CF is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, which encodes an ion channel important for maintaining the proper hydration of pulmonary surfaces. When CFTR function is ablated or impaired, airways develop thickened, adherent mucus that contributes to a vicious cycle of infection and inflammation. Therapeutics for pwCF, called CFTR modulators, target the CFTR defect directly, restoring airway surface hydration and mucociliary clearance. However, even with CFTR modulator therapy, bacterial infections persist. To develop a relevant model of diseased airway epithelium, we established a primary human airway epithelium culture system with persistent Pseudomonas aeruginosa infection. We used this model to examine the effects of CFTR modulators on CFTR maturation, CFTR function, and bacterial persistence. We found that the presence of P. aeruginosa increased CFTR mRNA, protein, and function. We also found that CFTR modulators caused a decrease in P. aeruginosa burden. These results demonstrate the importance of including live bacteria to accurately model the CF lung, and that understanding the effects of infection on CFTR rescue by CFTR modulators is critical to evaluating and optimizing drug therapies for all pwCF.
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Affiliation(s)
- Deborah M. Cholon
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
| | - Matthew A. Greenwald
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Matthew G. Higgs
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Nancy L. Quinney
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
| | - Susan E. Boyles
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
| | - Suzanne L. Meinig
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
- Pharmaceutical Product Development (PPD), Thermo Fisher Scientific, Morrisville, NC 27560, USA
| | - John T. Minges
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
| | - Ashlesha Chaubal
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
| | - Robert Tarran
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
- Division of Genetic, Department of Internal Medicine, Environmental and Inhalational Disease, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Carla M. P. Ribeiro
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
- Division of Pulmonary Diseases, Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Matthew C. Wolfgang
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Martina Gentzsch
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; (D.M.C.); (M.A.G.)
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Division of Pediatric Pulmonology, Department of Pediatrics, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
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3
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Ruan J, Liang D, Yan W, Zhong Y, Talley DC, Rai G, Tao D, LeClair CA, Simeonov A, Zhang Y, Chen F, Quinney NL, Boyles SE, Cholon DM, Gentzsch M, Henderson MJ, Xue F, Fang S. A small-molecule inhibitor and degrader of the RNF5 ubiquitin ligase. Mol Biol Cell 2022; 33:ar120. [PMID: 36074076 PMCID: PMC9634977 DOI: 10.1091/mbc.e22-06-0233] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
RNF5 E3 ubiquitin ligase has multiple biological roles and has been linked to the development of severe diseases such as cystic fibrosis, acute myeloid leukemia, and certain viral infections, emphasizing the importance of discovering small-molecule RNF5 modulators for research and drug development. The present study describes the synthesis of a new benzo[b]thiophene derivative, FX12, that acts as a selective small-molecule inhibitor and degrader of RNF5. We initially identified the previously reported STAT3 inhibitor, Stattic, as an inhibitor of dislocation of misfolded proteins from the endoplasmic reticulum (ER) lumen to the cytosol in ER-associated degradation. A concise structure-activity relationship campaign (SAR) around the Stattic chemotype led to the synthesis of FX12, which has diminished activity in inhibition of STAT3 activation and retains dislocation inhibitory activity. FX12 binds to RNF5 and inhibits its E3 activity in vitro as well as promoting proteasomal degradation of RNF5 in cells. RNF5 as a molecular target for FX12 was supported by the facts that FX12 requires RNF5 to inhibit dislocation and negatively regulates RNF5 function. Thus, this study developed a small-molecule inhibitor and degrader of the RNF5 ubiquitin ligase, providing a chemical biology tool for RNF5 research and therapeutic development.
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Affiliation(s)
- Jingjing Ruan
- Center for Biomedical Engineering and Technology, Department of Physiology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201,First Affiliated Hospital and
| | - Dongdong Liang
- University of Maryland School of Pharmacy, Baltimore, MD 21201
| | - Wenjing Yan
- Center for Biomedical Engineering and Technology, Department of Physiology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Yongwang Zhong
- Center for Biomedical Engineering and Technology, Department of Physiology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Daniel C. Talley
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850
| | - Ganesha Rai
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850
| | - Dingyin Tao
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850
| | - Christopher A. LeClair
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850
| | - Yinghua Zhang
- Center for Innovative Biomedical Resources, Biosensor Core, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Feihu Chen
- School of Pharmacy, Anhui Medical University, Hefei, Anhui 230032, China
| | | | | | | | - Martina Gentzsch
- Marsico Lung Institute and Cystic Fibrosis Research Center,Department of Pediatric Pulmonology, and,Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Mark J. Henderson
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850,*Address corespondence to: Shengyun Fang (lead contact) (); Mark J. Henderson (); Fengtian Xue ()
| | - Fengtian Xue
- University of Maryland School of Pharmacy, Baltimore, MD 21201,*Address corespondence to: Shengyun Fang (lead contact) (); Mark J. Henderson (); Fengtian Xue ()
| | - Shengyun Fang
- Center for Biomedical Engineering and Technology, Department of Physiology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201,*Address corespondence to: Shengyun Fang (lead contact) (); Mark J. Henderson (); Fengtian Xue ()
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4
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Lee RE, Lewis CA, He L, Bulik-Sullivan EC, Gallant SC, Mascenik TM, Dang H, Cholon DM, Gentzsch M, Morton LC, Minges JT, Theile JW, Castle NA, Knowles MR, Kimple AJ, Randell SH. Small molecule eRF3a degraders rescue CFTR nonsense mutations by promoting premature termination codon readthrough. J Clin Invest 2022; 132:154571. [PMID: 35900863 PMCID: PMC9479597 DOI: 10.1172/jci154571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 07/26/2022] [Indexed: 11/22/2022] Open
Abstract
The vast majority of people with cystic fibrosis (CF) are now eligible for CF transmembrane regulator (CFTR) modulator therapy. The remaining individuals with CF harbor premature termination codons (PTCs) or rare CFTR variants with limited treatment options. Although the clinical modulator response can be reliably predicted using primary airway epithelial cells, primary cells carrying rare CFTR variants are scarce. To overcome this obstacle, cell lines can be created by overexpression of mouse Bmi-1 and human TERT (hTERT). Using this approach, we developed 2 non-CF and 6 CF airway epithelial cell lines, 3 of which were homozygous for the W1282X PTC variant. The Bmi-1/hTERT cell lines recapitulated primary cell morphology and ion transport function. The 2 F508del-CFTR cell lines responded robustly to CFTR modulators, which was mirrored in the parent primary cells and in the cell donors’ clinical response. Cereblon E3 ligase modulators targeting eukaryotic release factor 3a (eRF3a) rescued W1282X-CFTR function to approximately 20% of WT levels and, when paired with G418, rescued G542X-CFTR function to approximately 50% of WT levels. Intriguingly, eRF3a degraders also diminished epithelial sodium channel (ENaC) function. These studies demonstrate that Bmi-1/hTERT cell lines faithfully mirrored primary cell responses to CFTR modulators and illustrate a therapeutic approach to rescue CFTR nonsense mutations.
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Affiliation(s)
- Rhianna E Lee
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Catherine A Lewis
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Lihua He
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Emily C Bulik-Sullivan
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Samuel C Gallant
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Teresa M Mascenik
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Hong Dang
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Martina Gentzsch
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Lisa C Morton
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - John T Minges
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | | | - Neil A Castle
- Research and Development, Icagen, Durham, United States of America
| | - Michael R Knowles
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Adam J Kimple
- Department of Otolaryngology, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
| | - Scott H Randell
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, United States of America
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5
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Cholon DM, Gentzsch M. Established and novel human translational models to advance cystic fibrosis research, drug discovery, and optimize CFTR-targeting therapeutics. Curr Opin Pharmacol 2022; 64:102210. [DOI: 10.1016/j.coph.2022.102210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/24/2022] [Accepted: 03/07/2022] [Indexed: 12/16/2022]
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6
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He L, Kennedy AS, Houck S, Aleksandrov A, Quinney NL, Cyr-Scully A, Cholon DM, Gentzsch M, Randell SH, Ren HY, Cyr DM. DNAJB12 and Hsp70 triage arrested intermediates of N1303K-CFTR for endoplasmic reticulum-associated autophagy. Mol Biol Cell 2021; 32:538-553. [PMID: 33534640 PMCID: PMC8101465 DOI: 10.1091/mbc.e20-11-0688] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/19/2021] [Accepted: 01/26/2021] [Indexed: 11/11/2022] Open
Abstract
The transmembrane Hsp40 DNAJB12 and cytosolic Hsp70 cooperate on the endoplasmic reticulum's (ER) cytoplasmic face to facilitate the triage of nascent polytopic membrane proteins for folding versus degradation. N1303K is a common mutation that causes misfolding of the ion channel CFTR, but unlike F508del-CFTR, biogenic and functional defects in N1303K-CFTR are resistant to correction by folding modulators. N1303K is reported to arrest CFTR folding at a late stage after partial assembly of its N-terminal domains. N1303K-CFTR intermediates are clients of JB12-Hsp70 complexes, maintained in a detergent-soluble state, and have a relatively long 3-h half-life. ER-associated degradation (ERAD)-resistant pools of N1303K-CFTR are concentrated in ER tubules that associate with autophagy initiation sites containing WIPI1, FlP200, and LC3. Destabilization of N1303K-CFTR or depletion of JB12 prevents entry of N1303K-CFTR into the membranes of ER-connected phagophores and traffic to autolysosomes. In contrast, the stabilization of intermediates with the modulator VX-809 promotes the association of N1303K-CFTR with autophagy initiation machinery. N1303K-CFTR is excluded from the ER-exit sites, and its passage from the ER to autolysosomes does not require ER-phagy receptors. DNAJB12 operates in biosynthetically active ER microdomains to triage membrane protein intermediates in a conformation-specific manner for secretion versus degradation via ERAD or selective-ER-associated autophagy.
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Affiliation(s)
- Lihua He
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Andrew S. Kennedy
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Scott Houck
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Andrei Aleksandrov
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Nancy L. Quinney
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Alexandra Cyr-Scully
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Deborah M. Cholon
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Martina Gentzsch
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Scott H. Randell
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Hong Yu Ren
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Douglas M. Cyr
- Department of Cell Biology and Physiology and the Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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7
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Gentzsch M, Cholon DM, Quinney NL, Martino MEB, Minges JT, Boyles SE, Guhr Lee TN, Esther CR, Ribeiro CMP. Airway Epithelial Inflammation In Vitro Augments the Rescue of Mutant CFTR by Current CFTR Modulator Therapies. Front Pharmacol 2021; 12:628722. [PMID: 33859562 PMCID: PMC8042279 DOI: 10.3389/fphar.2021.628722] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/01/2021] [Indexed: 12/28/2022] Open
Abstract
In cystic fibrosis (CF), defective biogenesis and activity of the cystic fibrosis transmembrane conductance regulator (CFTR) leads to airway dehydration and impaired mucociliary clearance, resulting in chronic airway infection and inflammation. The most common CFTR mutation, F508del, results in a processing defect in which the protein is retained in the endoplasmic reticulum and does not reach the apical surface. CFTR corrector compounds address this processing defect to promote mutant CFTR transfer to the apical membrane. When coupled with potentiators to increase CFTR channel activity, these drugs yield significant clinical benefits in CF patients carrying the F508del mutation. However, processing of CFTR and other proteins can be influenced by environmental factors such as inflammation, and the impact of airway inflammation on pharmacological activity of CFTR correctors is not established. The present study evaluated CFTR-rescuing therapies in inflamed CF airway epithelial cultures, utilizing models that mimic the inflammatory environment of CF airways. Primary bronchial epithelial cultures from F508del/F508del CF patients were inflamed by mucosal exposure to one of two inflammatory stimuli: 1) supernatant from mucopurulent material from CF airways with advanced lung disease, or 2) bronchoalveolar lavage fluid from pediatric CF patients. Cultures inflamed with either stimulus exhibited augmented F508del responses following therapy with correctors VX-809 or VX-661, and overcame the detrimental effects of chronic exposure to the CFTR potentiator VX-770. Remarkably, even the improved CFTR rescue responses resulting from a clinically effective triple therapy (VX-659/VX-661/VX-770) were enhanced by epithelial inflammation. Thus, the airway inflammatory milieu from late- and early-stage CF lung disease improves the efficacy of CFTR modulators, regardless of the combination therapy used. Our findings suggest that pre-clinical evaluation of CFTR corrector therapies should be performed under conditions mimicking the native inflammatory status of CF airways, and altering the inflammatory status of CF airways may change the efficacy of CFTR modulator therapies.
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Affiliation(s)
- Martina Gentzsch
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States.,Department of Pediatrics, Division of Pediatric Pulmonology, School of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, United States.,Department of Cell Biology and Physiology, School of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Deborah M Cholon
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - Nancy L Quinney
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - Mary E B Martino
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - John T Minges
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - Susan E Boyles
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - Tara N Guhr Lee
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - Charles R Esther
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States.,Department of Pediatrics, Division of Pediatric Pulmonology, School of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Carla M P Ribeiro
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States.,Department of Cell Biology and Physiology, School of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, United States.,Department of Medicine, Division of Pulmonary Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
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8
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McCravy MS, Quinney NL, Cholon DM, Boyles SE, Jensen TJ, Aleksandrov AA, Donaldson SH, Noone PG, Gentzsch M. Personalised medicine for non-classic cystic fibrosis resulting from rare CFTR mutations. Eur Respir J 2020; 56:13993003.00062-2020. [PMID: 32265312 DOI: 10.1183/13993003.00062-2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 03/16/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Matthew S McCravy
- Dept of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Nancy L Quinney
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC, USA
| | - Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC, USA
| | - Susan E Boyles
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC, USA
| | - Timothy J Jensen
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC, USA
| | - Andrei A Aleksandrov
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC, USA.,Dept of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, USA
| | - Scott H Donaldson
- Dept of Medicine, University of North Carolina, Chapel Hill, NC, USA.,Division of Pulmonary Diseases and Critical Care Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Peadar G Noone
- Dept of Medicine, University of North Carolina, Chapel Hill, NC, USA.,Division of Pulmonary Diseases and Critical Care Medicine, University of North Carolina, Chapel Hill, NC, USA.,M. Gentzsch and P.G. Noone contributed equally to this article as lead authors and supervised the work
| | - Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC, USA .,Dept of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC, USA.,M. Gentzsch and P.G. Noone contributed equally to this article as lead authors and supervised the work
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9
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Guhr Lee TN, Cholon DM, Quinney NL, Gentzsch M, Esther CR. Accumulation and persistence of ivacaftor in airway epithelia with prolonged treatment. J Cyst Fibros 2020; 19:746-751. [PMID: 32536510 DOI: 10.1016/j.jcf.2020.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/17/2020] [Accepted: 04/21/2020] [Indexed: 01/27/2023]
Abstract
BACKGROUND Current dosing strategies of CFTR modulators are based on serum pharmacokinetics, but drug concentrations in target tissues such as airway epithelia are not known. Previous data suggest that CFTR modulators may accumulate in airway epithelia, and serum pharmacokinetics may not accurately predict effects of chronic treatment. METHODS CF (F508del homozygous) primary human bronchial epithelial (HBE) cells grown at air-liquid interface were treated for 14 days with ivacaftor plus lumacaftor or ivacaftor plus tezacaftor, followed by a 14-day washout period. At various intervals during treatment and washout phases, drug concentrations were measured via mass spectrometry, electrophysiological function was assessed in Ussing chambers, and mature CFTR protein was quantified by Western blotting. RESULTS During treatment, ivacaftor accumulated in CF-HBEs to a much greater extent than either lumacaftor or tezacaftor and remained persistently elevated even after 14 days of washout. CFTR activity peaked at 7 days of treatment but diminished with further ivacaftor accumulation, though remained above baseline even after washout. CONCLUSIONS Intracellular accrual and persistence of CFTR modulators during and after chronic treatment suggest complex pharmacokinetic and pharmacodynamic properties within airway epithelia that are not predicted by serum pharmacokinetics. Direct measurement of drugs in target tissues may be needed to optimize dosing strategies, and the persistence of CFTR modulators after treatment cessation has implications for personalized medicine approaches.
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Affiliation(s)
- Tara N Guhr Lee
- Division of Pediatric Pulmonology, Department of Pediatrics, University of North Carolina School of Medicine, 450-D MacNider Hall, Campus Box 7217, Chapel Hill, NC 27599-7217, USA; Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Nancy L Quinney
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Charles R Esther
- Division of Pediatric Pulmonology, Department of Pediatrics, University of North Carolina School of Medicine, 450-D MacNider Hall, Campus Box 7217, Chapel Hill, NC 27599-7217, USA; Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
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Tomati V, Caci E, Ferrera L, Pesce E, Sondo E, Cholon DM, Quinney NL, Boyles SE, Armirotti A, Ravazzolo R, Galietta LJ, Gentzsch M, Pedemonte N. Thymosin α-1 does not correct F508del-CFTR in cystic fibrosis airway epithelia. JCI Insight 2019; 4:128935. [DOI: 10.1172/jci.insight.128935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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11
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Gentzsch M, Cholon DM, Quinney NL, Boyles SE, Martino MEB, Ribeiro CMP. The cystic fibrosis airway milieu enhances rescue of F508del in a pre-clinical model. Eur Respir J 2018; 52:13993003.01133-2018. [PMID: 30287473 DOI: 10.1183/13993003.01133-2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/22/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Martina Gentzsch
- Marsico Lung Institute and Cystic Fibrosis Research Center, Chapel Hill, NC, USA.,Dept of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC, USA
| | - Deborah M Cholon
- Marsico Lung Institute and Cystic Fibrosis Research Center, Chapel Hill, NC, USA
| | - Nancy L Quinney
- Marsico Lung Institute and Cystic Fibrosis Research Center, Chapel Hill, NC, USA
| | - Susan E Boyles
- Marsico Lung Institute and Cystic Fibrosis Research Center, Chapel Hill, NC, USA
| | - Mary E B Martino
- Marsico Lung Institute and Cystic Fibrosis Research Center, Chapel Hill, NC, USA
| | - Carla M P Ribeiro
- Marsico Lung Institute and Cystic Fibrosis Research Center, Chapel Hill, NC, USA.,Dept of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, NC, USA.,Dept of Medicine, The University of North Carolina, Chapel Hill, NC, USA
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12
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Tomati V, Caci E, Ferrera L, Pesce E, Sondo E, Cholon DM, Quinney NL, Boyles SE, Armirotti A, Ravazzolo R, Galietta LJ, Gentzsch M, Pedemonte N. Thymosin α-1 does not correct F508del-CFTR in cystic fibrosis airway epithelia. JCI Insight 2018; 3:98699. [PMID: 29415893 DOI: 10.1172/jci.insight.98699] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 12/28/2017] [Indexed: 12/29/2022] Open
Abstract
In cystic fibrosis (CF), deletion of phenylalanine 508 (F508del) in the cystic fibrosis transmembrane conductance regulator (CFTR) anion channel causes misfolding and premature degradation. Considering the numerous effects of the F508del mutation on the assembly and processing of CFTR protein, combination therapy with several pharmacological correctors is likely to be required to treat CF patients. Recently, it has been reported that thymosin α-1 (Tα-1) has multiple beneficial effects that could lead to a single-molecule-based therapy for CF patients with F508del. Such effects include suppression of inflammation, improvement in F508del-CFTR maturation and gating, and stimulation of chloride secretion through the calcium-activated chloride channel (CaCC). Given the importance of such a drug, we aimed to characterize the underlying molecular mechanisms of action of Tα-1. In-depth analysis of Tα-1 effects was performed using well-established microfluorimetric, biochemical, and electrophysiological techniques on epithelial cell lines and primary bronchial epithelial cells from CF patients. The studies, which were conducted in 2 independent laboratories with identical outcome, demonstrated that Tα-1 is devoid of activity on mutant CFTR as well as on CaCC. Although Tα-1 may still be useful as an antiinflammatory agent, its ability to target defective anion transport in CF remains to be further investigated.
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Affiliation(s)
- Valeria Tomati
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy
| | - Emanuela Caci
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy
| | - Loretta Ferrera
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy
| | - Emanuela Pesce
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy
| | - Elvira Sondo
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy
| | - Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Nancy L Quinney
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Susan E Boyles
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Andrea Armirotti
- Fondazione Istituto Italiano di Tecnologia, Analytical Chemistry Lab, Genova, Italy
| | - Roberto Ravazzolo
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy.,University of Genova, DINOGMI Department, Genova, Italy
| | - Luis Jv Galietta
- Telethon Institute for Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Gentzsch M, Ren HY, Houck SA, Quinney NL, Cholon DM, Sopha P, Chaudhry IG, Das J, Dokholyan NV, Randell SH, Cyr DM. Restoration of R117H CFTR folding and function in human airway cells through combination treatment with VX-809 and VX-770. Am J Physiol Lung Cell Mol Physiol 2016; 311:L550-9. [PMID: 27402691 DOI: 10.1152/ajplung.00186.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 06/24/2016] [Indexed: 01/06/2023] Open
Abstract
Cystic fibrosis (CF) is a lethal recessive genetic disease caused primarily by the F508del mutation in the CF transmembrane conductance regulator (CFTR). The potentiator VX-770 was the first CFTR modulator approved by the FDA for treatment of CF patients with the gating mutation G551D. Orkambi is a drug containing VX-770 and corrector VX809 and is approved for treatment of CF patients homozygous for F508del, which has folding and gating defects. At least 30% of CF patients are heterozygous for the F508del mutation with the other allele encoding for one of many different rare CFTR mutations. Treatment of heterozygous F508del patients with VX-809 and VX-770 has had limited success, so it is important to identify heterozygous patients that respond to CFTR modulator therapy. R117H is a more prevalent rare mutation found in over 2,000 CF patients. In this study we investigated the effectiveness of VX-809/VX-770 therapy on restoring CFTR function in human bronchial epithelial (HBE) cells from R117H/F508del CF patients. We found that VX-809 stimulated more CFTR activity in R117H/F508del HBEs than in F508del/F508del HBEs. R117H expressed exclusively in immortalized HBEs exhibited a folding defect, was retained in the ER, and degraded prematurely. VX-809 corrected the R117H folding defect and restored channel function. Because R117 is involved in ion conductance, VX-770 acted additively with VX-809 to restore CFTR function in chronically treated R117H/F508del cells. Although treatment of R117H patients with VX-770 has been approved, our studies indicate that Orkambi may be more beneficial for rescue of CFTR function in these patients.
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Affiliation(s)
- Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina; Department of Cell Biology and Physiology. University of North Carolina, Chapel Hill, North Carolina; and
| | - Hong Y Ren
- Department of Cell Biology and Physiology. University of North Carolina, Chapel Hill, North Carolina; and
| | - Scott A Houck
- Department of Cell Biology and Physiology. University of North Carolina, Chapel Hill, North Carolina; and
| | - Nancy L Quinney
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina
| | - Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina
| | - Pattarawut Sopha
- Department of Cell Biology and Physiology. University of North Carolina, Chapel Hill, North Carolina; and
| | - Imron G Chaudhry
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina; Department of Cell Biology and Physiology. University of North Carolina, Chapel Hill, North Carolina; and
| | - Jhuma Das
- Department of Biochemistry, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Nikolay V Dokholyan
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina; Department of Biochemistry, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Scott H Randell
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina; Department of Cell Biology and Physiology. University of North Carolina, Chapel Hill, North Carolina; and
| | - Douglas M Cyr
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina, Chapel Hill, North Carolina; Department of Cell Biology and Physiology. University of North Carolina, Chapel Hill, North Carolina; and
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Cholon DM, Esther CR, Gentzsch M. Efficacy of lumacaftor-ivacaftor for the treatment of cystic fibrosis patients homozygous for the F508del-CFTR mutation. Expert Rev Precis Med Drug Dev 2016; 1:235-243. [PMID: 27482545 DOI: 10.1080/23808993.2016.1175299] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cystic fibrosis (CF) results from mutations in the CF transmembrane conductance regulator (CFTR) gene, which codes for the CFTR channel protein. The most common mutation in CF is F508del, which produces a misfolded protein with diminished channel activity. The development of small-molecule CFTR-modulator compounds offers an exciting and novel approach for pharmacological treatment of CF. The corrector lumacaftor helps rescue F508del-CFTR to the cell surface, and potentiator ivacaftor increases F508del-CFTR channel activity. The combination of lumacaftor-ivacaftor (Vertex Pharmaceuticals Incorporated) represents the first FDA-approved therapy for CF patients with two copies of the F508del mutation. Although this combination therapy is the first treatment to directly target the F508del-CFTR mutation, patients taking this drug displayed only modest improvements in lung function. This article summarizes recent data from clinical trials and research discoveries relating to the lumacaftor-ivacaftor treatment, and considers options for identifying future therapies that will be most efficacious for all CF patients.
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Affiliation(s)
- Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Charles R Esther
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Division of Pediatric Pulmonology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Cholon DM, Quinney NL, Fulcher ML, Esther CR, Das J, Dokholyan NV, Randell SH, Boucher RC, Gentzsch M. Potentiator ivacaftor abrogates pharmacological correction of ΔF508 CFTR in cystic fibrosis. Sci Transl Med 2015; 6:246ra96. [PMID: 25101886 DOI: 10.1126/scitranslmed.3008680] [Citation(s) in RCA: 256] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR). Newly developed "correctors" such as lumacaftor (VX-809) that improve CFTR maturation and trafficking and "potentiators" such as ivacaftor (VX-770) that enhance channel activity may provide important advances in CF therapy. Although VX-770 has demonstrated substantial clinical efficacy in the small subset of patients with a mutation (G551D) that affects only channel activity, a single compound is not sufficient to treat patients with the more common CFTR mutation, ΔF508. Thus, patients with ΔF508 will likely require treatment with both correctors and potentiators to achieve clinical benefit. However, whereas the effectiveness of acute treatment with this drug combination has been demonstrated in vitro, the impact of chronic therapy has not been established. In studies of human primary airway epithelial cells, we found that both acute and chronic treatment with VX-770 improved CFTR function in cells with the G551D mutation, consistent with clinical studies. In contrast, chronic VX-770 administration caused a dose-dependent reversal of VX-809-mediated CFTR correction in ΔF508 homozygous cultures. This result reflected the destabilization of corrected ΔF508 CFTR by VX-770, markedly increasing its turnover rate. Chronic VX-770 treatment also reduced mature wild-type CFTR levels and function. These findings demonstrate that chronic treatment with CFTR potentiators and correctors may have unexpected effects that cannot be predicted from short-term studies. Combining these drugs to maximize rescue of ΔF508 CFTR may require changes in dosing and/or development of new potentiator compounds that do not interfere with CFTR stability.
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Affiliation(s)
- Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nancy L Quinney
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - M Leslie Fulcher
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Charles R Esther
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Division of Pediatric Pulmonology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jhuma Das
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nikolay V Dokholyan
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Scott H Randell
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Richard C Boucher
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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Cholon DM, O'Neal WK, Randell SH, Riordan JR, Gentzsch M. Modulation of endocytic trafficking and apical stability of CFTR in primary human airway epithelial cultures. Am J Physiol Lung Cell Mol Physiol 2009; 298:L304-14. [PMID: 20008117 DOI: 10.1152/ajplung.00016.2009] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
CFTR is a highly regulated apical chloride channel of epithelial cells that is mutated in cystic fibrosis (CF). In this study, we characterized the apical stability and intracellular trafficking of wild-type and mutant CFTR in its native environment, i.e., highly differentiated primary human airway epithelial (HAE) cultures. We labeled the apical pool of CFTR and subsequently visualized the protein in intracellular compartments. CFTR moved from the apical surface to endosomes and then efficiently recycled back to the surface. CFTR endocytosis occurred more slowly in polarized than in nonpolarized HAE cells or in a polarized epithelial cell line. The most common mutation in CF, DeltaF508 CFTR, was rescued from endoplasmic reticulum retention by low-temperature incubation but transited from the apical membrane to endocytic compartments more rapidly and recycled less efficiently than wild-type CFTR. Incubation with small-molecule correctors resulted in DeltaF508 CFTR at the apical membrane but did not restore apical stability. To stabilize the mutant protein at the apical membrane, we found that the dynamin inhibitor Dynasore and the cholesterol-extracting agent cyclodextrin dramatically reduced internalization of DeltaF508, whereas the proteasomal inhibitor MG-132 completely blocked endocytosis of DeltaF508. On examination of intrinsic properties of CFTR that may affect its apical stability, we found that N-linked oligosaccharides were not necessary for transport to the apical membrane but were required for efficient apical recycling and, therefore, influenced the turnover of surface CFTR. Thus apical stability of CFTR in its native environment is affected by properties of the protein and modulation of endocytic trafficking.
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Affiliation(s)
- Deborah M Cholon
- Cystic Fibrosis Research Center and Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7248, USA
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