151
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Trimble AT, Donaldson SH. CFTR Modulator Therapies for Cystic Fibrosis. PEDIATRIC ALLERGY, IMMUNOLOGY, AND PULMONOLOGY 2015; 28:230-236. [PMID: 35923001 DOI: 10.1089/ped.2015.0583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The cloning of cystic fibrosis transmembrane conductance regulator (CFTR) set into motion a cascade of discoveries that have helped to reveal the underlying pathophysiologic basis of cystic fibrosis (CF). This discovery and the knowledge that followed have also provided the opportunity to target this basic defect, with the hope of reversing or preventing the serious clinical consequences that result from absent CFTR function. With the recent approval of 2 therapies that directly modulate CFTR function in more than half of the CF population, we are now at the beginning of a pathway to providing increasingly effective therapies that have the potential to provide a fundamental change in the outcome of most patients with CF.
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Affiliation(s)
- Aaron T Trimble
- Division of Pulmonary and Critical Care Medicine, Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Scott H Donaldson
- Division of Pulmonary and Critical Care Medicine, Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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152
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Farinha CM, Matos P. Repairing the basic defect in cystic fibrosis - one approach is not enough. FEBS J 2015; 283:246-64. [PMID: 26416076 DOI: 10.1111/febs.13531] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/21/2015] [Accepted: 09/23/2015] [Indexed: 12/16/2022]
Abstract
Cystic fibrosis has attracted much attention in recent years due to significant advances in the pharmacological targeting of the basic defect underlying this recessive disorder: the deficient functional expression of mutant cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels at the apical membrane of epithelial cells. However, increasing evidence points to the reduced efficacy of single treatments, thus reinforcing the need to combine several therapeutic strategies to effectively target the multiple basic defect(s). Protein-repair therapies that use potentiators (activating membrane-located CFTR) or correctors (promoting the relocation of intracellular-retained trafficking mutants of CFTR) in frequent mutations such as F508del and G551D have been put forward and made their way to the clinic with moderate to good efficiency. However, alternative (or additional) approaches targeting the membrane stability of mutant proteins, or correcting the cellular phenotype through a direct effect upon other ion channels (affecting the overall electrolyte transport or simply promoting alternative chloride transport) or targeting less frequent mutations (splicing variants, for example), have been proposed and tested in the field of cystic fibrosis (CF). Here, we cover the different strategies that rely on novel findings concerning the CFTR interactome and signalosome through which it might be possible to further influence the cellular trafficking and post-translational modification machinery (to increase rescued CFTR abundance and membrane stability). We also highlight the new data on strategies aiming at the regulation of sodium absorption or to increase chloride transport through alternative channels. The development and implementation of these complementary approaches will pave the way to combinatorial therapeutic strategies with increased benefit to CF patients.
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Affiliation(s)
- Carlos M Farinha
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Portugal
| | - Paulo Matos
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Portugal.,Department of Human Genetics, National Health Institute 'Dr. Ricardo Jorge', Lisboa, Portugal
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153
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Mou H, Brazauskas K, Rajagopal J. Personalized medicine for cystic fibrosis: establishing human model systems. Pediatr Pulmonol 2015; 50 Suppl 40:S14-23. [PMID: 26335952 DOI: 10.1002/ppul.23233] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 05/26/2015] [Indexed: 12/16/2022]
Abstract
With over 1,500 identifiable mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that result in distinct functional and phenotypical abnormalities, it is virtually impossible to perform randomized clinical trials to identify the best therapeutics for all patients. Therefore, a personalized medicine approach is essential. The only way to realistically accomplish this is through the development of improved in vitro human model systems. The lack of a readily available and infinite supply of human CFTR-expressing airway epithelial cells is a key bottleneck. We propose that a concerted two-pronged approach is necessary for patient-specific cystic fibrosis research to continue to prosper and realize its potential: (1) more effective culture and differentiation conditions for growing primary human airway and nasal epithelial cells and (2) the development of collective protocols for efficiently differentiating disease- and patient-specific induced pluripotent stem cells (iPSC) into pure populations of adult epithelial cells. Ultimately, we need a personalized human model system for cystic fibrosis with the capacity for uncomplicated bankability, widespread availability, and universal applicability for patient-specific disease modeling, novel pharmacotherapy investigation and screening, and readily executable genetic modification.
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Affiliation(s)
- Hongmei Mou
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts.,Pediatric Pulmonary Medicine, Massachusetts General Hospital for Children, Boston, Massachusetts
| | - Karissa Brazauskas
- Pediatric Pulmonary Medicine, Massachusetts General Hospital for Children, Boston, Massachusetts
| | - Jayaraj Rajagopal
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts.,Pulmonary Critical Care Unit, Internal Medicine and Pediatrics, Massachusetts General Hospital, Boston, Massachusetts
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154
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Solomon GM, Marshall SG, Ramsey BW, Rowe SM. Breakthrough therapies: Cystic fibrosis (CF) potentiators and correctors. Pediatr Pulmonol 2015; 50 Suppl 40:S3-S13. [PMID: 26097168 PMCID: PMC4620567 DOI: 10.1002/ppul.23240] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/29/2015] [Accepted: 06/03/2015] [Indexed: 12/28/2022]
Abstract
Cystic Fibrosis is caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene resulting in abnormal protein function. Recent advances of targeted molecular therapies and high throughput screening have resulted in multiple drug therapies that target many important mutations in the CFTR protein. In this review, we provide the latest results and current progress of CFTR modulators for the treatment of cystic fibrosis, focusing on potentiators of CFTR channel gating and Phe508del processing correctors for the Phe508del CFTR mutation. Special emphasis is placed on the molecular basis underlying these new therapies and emerging results from the latest clinical trials. The future directions for augmenting the rescue of Phe508del with CFTR modulators are also emphasized.
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Affiliation(s)
- George M Solomon
- Department of Medicine and the Gregory Fleming James Cystic Fibrosis Research Center, Birmingham, Alabama
| | - Susan G Marshall
- Division of Pulmonary Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington
| | - Bonnie W Ramsey
- Division of Pulmonary Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington.,Center for Clinical and Translational Research, Seattle Children's Research Institute, Seattle, Washington
| | - Steven M Rowe
- Department of Medicine and the Gregory Fleming James Cystic Fibrosis Research Center, Birmingham, Alabama.,Departments of Medicine, Pediatrics, Cell Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
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155
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Abstract
Cystic fibrosis is the most common genetically determined, life-limiting disorder in populations of European ancestry. The genetic basis of cystic fibrosis is well established to be mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that codes for an apical membrane chloride channel principally expressed by epithelial cells. Conventional approaches to cystic fibrosis care involve a heavy daily burden of supportive treatments to combat lung infection, help clear airway secretions and maintain nutritional status. In 2012, a new era of precision medicine in cystic fibrosis therapeutics began with the licensing of a small molecule, ivacaftor, which successfully targets the underlying defect and improves CFTR function in a subgroup of patients in a genotype-specific manner. Here, we review the three main targeted approaches that have been adopted to improve CFTR function: potentiators, which recover the function of CFTR at the apical surface of epithelial cells that is disrupted in class III and IV genetic mutations; correctors, which improve intracellular processing of CFTR, increasing surface expression, in class II mutations; and production correctors or read-through agents, which promote transcription of CFTR in class I mutations. The further development of such approaches offers great promise for future therapeutic strategies in cystic fibrosis.
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156
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De Stefano D, Villella VR, Esposito S, Tosco A, Sepe A, De Gregorio F, Salvadori L, Grassia R, Leone CA, De Rosa G, Maiuri MC, Pettoello-Mantovani M, Guido S, Bossi A, Zolin A, Venerando A, Pinna LA, Mehta A, Bona G, Kroemer G, Maiuri L, Raia V. Restoration of CFTR function in patients with cystic fibrosis carrying the F508del-CFTR mutation. Autophagy 2015; 10:2053-74. [PMID: 25350163 PMCID: PMC4502695 DOI: 10.4161/15548627.2014.973737] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Restoration of BECN1/Beclin 1-dependent autophagy and depletion of SQSTM1/p62 by genetic manipulation or autophagy-stimulatory proteostasis regulators, such as cystamine, have positive effects on mouse models of human cystic fibrosis (CF). These measures rescue the functional expression of the most frequent pathogenic CFTR mutant, F508del, at the respiratory epithelial surface and reduce lung inflammation in CftrF508del homozygous mice. Cysteamine, the reduced form of cystamine, is an FDA-approved drug. Here, we report that oral treatment with cysteamine greatly reduces the mortality rate and improves the phenotype of newborn mice bearing the F508del-CFTR mutation. Cysteamine was also able to increase the plasma membrane expression of the F508del-CFTR protein in nasal epithelial cells from F508del homozygous CF patients, and these effects persisted for 24 h after cysteamine withdrawal. Importantly, this cysteamine effect after washout was further sustained by the sequential administration of epigallocatechin gallate (EGCG), a green tea flavonoid, both in vivo, in mice, and in vitro, in primary epithelial cells from CF patients. In a pilot clinical trial involving 10 F508del-CFTR homozygous CF patients, the combination of cysteamine and EGCG restored BECN1, reduced SQSTM1 levels and improved CFTR function from nasal epithelial cells in vivo, correlating with a decrease of chloride concentrations in sweat, as well as with a reduction of the abundance of TNF/TNF-alpha (tumor necrosis factor) and CXCL8 (chemokine [C-X-C motif] ligand 8) transcripts in nasal brushing and TNF and CXCL8 protein levels in the sputum. Altogether, these results suggest that optimal schedules of cysteamine plus EGCG might be used for the treatment of CF caused by the F508del-CFTR mutation.
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Key Words
- BECN1/Beclin 1, autophagy-related
- CF, cystic fibrosis
- CFTR
- CFTR, cystic fibrosis transmembrane conductance regulator
- CHX, cycloheximide
- CSNK2, casein kinase 2
- CXCL2, chemokine (C-X-C motif) ligand 2
- CXCL8, chemokine (C-X-C motif) ligand 8
- EGCG, epigallocatechin gallate
- FEV, forced expiratory volume
- PM, plasma membrane
- RPD, rectal potential difference
- SQSTM1, sequestosome 1
- TGM2, transglutaminase 2
- TNF, tumor necrosis factor
- autophagy
- cysteamine
- cystic fibrosis
- epigallocatechin gallate
- sweat chloride
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Affiliation(s)
- Daniela De Stefano
- a European Institute for Research in Cystic Fibrosis; Division of Genetics and Cell Biology; San Raffaele Scientific Institute ; Milan , Italy
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157
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Larsen MB, Hu J, Frizzell RA, Watkins SC. Simple image-based no-wash method for quantitative detection of surface expressed CFTR. Methods 2015; 96:40-45. [PMID: 26361332 DOI: 10.1016/j.ymeth.2015.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/04/2015] [Accepted: 09/05/2015] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is the most common lethal genetic disease among Caucasians. It is caused by mutations in the CF Transmembrane Conductance Regulator (CFTR) gene, which encodes an apical membrane anion channel that is required for regulating the volume and composition of epithelial secretions. The most common CFTR mutation, present on at least one allele in >90% of CF patients, deletes phenylalanine at position 508 (F508del), which causes the protein to misfold. Endoplasmic reticulum (ER) quality control elicits the degradation of mutant CFTR, compromising its trafficking to the epithelial cell apical membrane. The absence of functional CFTR leads to depletion of airway surface liquid, impaired clearance of mucus and bacteria from the lung, and predisposes to recurrent infections. Ultimately, respiratory failure results from inflammation and bronchiectasis. Although high throughput screening has identified small molecules that can restore the anion transport function of F508del CFTR, they correct less than 15% of WT CFTR activity, yielding insufficient clinical benefit. To date, most primary CF drug discovery assays have employed measurements of CFTR's anion transport function, a method that depends on the recruitment of a functional CFTR to the cell surface, involves multiple wash steps, and relies on a signal that saturates rapidly. Screening efforts have also included assays for detection of extracellularly HA-tagged or HRP-tagged CFTR, which require multiple washing steps. We have recently developed tools and cell lines that report the correction of mutant CFTR trafficking by currently available small molecules, and have extended this assay to the 96-well format. This new and simple no-wash assay of F508del CFTR at the cell surface may permit the discovery of more efficacious drugs, and hopefully thereby prevent the catastrophic effects of this disease. In addition, the modular design of this platform should make it useful for other diseases where loss-of-function results from folding and/or trafficking defects in membrane proteins.
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Affiliation(s)
- Mads Breum Larsen
- Department of Cell Biology and Physiology, Center for Biologic Imaging, University of Pittsburgh School of Medicine, 3500 Terrace Street, S233 BST, Pittsburgh, PA 15261, USA.
| | - Jennifer Hu
- Department of Cell Biology and Physiology, Center for Biologic Imaging, University of Pittsburgh School of Medicine, 3500 Terrace Street, S233 BST, Pittsburgh, PA 15261, USA.
| | - Raymond A Frizzell
- Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, 7116 Rangos Research Center, 4401 Penn Avenue, Pittsburgh, PA 15224, USA.
| | - Simon C Watkins
- Department of Cell Biology and Physiology, Center for Biologic Imaging, University of Pittsburgh School of Medicine, 3500 Terrace Street, S233 BST, Pittsburgh, PA 15261, USA.
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158
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Jai Y, Shah K, Bridges RJ, Bradbury NA. Evidence against resveratrol as a viable therapy for the rescue of defective ΔF508 CFTR. Biochim Biophys Acta Gen Subj 2015; 1850:2377-84. [PMID: 26342647 DOI: 10.1016/j.bbagen.2015.08.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/10/2015] [Accepted: 08/31/2015] [Indexed: 01/23/2023]
Abstract
BACKGROUND Resveratrol, a natural phenolic compound, has been reported to rescue mutant ΔF508 CFTR in expression systems and primary epithelial cells. Although this implies a therapeutic benefit to patients with CF, investigations were performed using resveratrol concentrations greatly in excess of those achievable in plasma. We evaluated the efficacy of resveratrol as a CFTR corrector in relevant primary airway cells, using physiologically achievable resveratrol concentrations. METHODS Cells expressing wt or ΔF508 CFTR were exposed to chronic or acute resveratrol. CFTR mRNA and protein expression were monitored. The effects of resveratrol on primary ΔF508 human airway cells were evaluated by equivalent current analysis using modified Ussing chambers. RESULTS Consistent with previously published data in heterologous expression systems, high doses of resveratrol increased CFTR expression; however physiologically relevant concentrations were without effect. In contrast to heterologous expression systems, resveratrol was unable to increase mutant CFTR channel activity in primary airway cells. Elevated amiloride-sensitive currents, indicative of sodium transport and characteristically elevated in CF airway cells, were also unaffected by resveratrol. CONCLUSIONS High concentrations of resveratrol can increase CFTR mRNA and protein in some cell types. In addition, acute resveratrol exposure can stimulate CFTR mediated chloride secretion, probably by increasing cellular cAMP levels. Resveratrol at physiologically achievable levels yielded no benefit in primary ΔF508 airway cells, either in terms of amiloride-sensitive currents of CFTR currents. GENERAL SIGNIFICANCE Taken together, our results do not support the use of resveratrol supplements as a therapy for patients with cystic fibrosis. It is possible that further modifications of the resveratrol backbone would yield a more efficacious compound.
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Affiliation(s)
- Ying Jai
- Department of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Kalpit Shah
- Department of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Robert J Bridges
- Department of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Neil A Bradbury
- Department of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA.
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159
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Lopes-Pacheco M, Boinot C, Sabirzhanova I, Morales MM, Guggino WB, Cebotaru L. Combination of Correctors Rescue ΔF508-CFTR by Reducing Its Association with Hsp40 and Hsp27. J Biol Chem 2015; 290:25636-45. [PMID: 26336106 DOI: 10.1074/jbc.m115.671925] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Indexed: 01/07/2023] Open
Abstract
Correcting the processing of ΔF508-CFTR, the most common mutation in cystic fibrosis, is the major goal in the development of new therapies for this disease. Here, we determined whether ΔF508 could be rescued by a combination of small-molecule correctors, and identified the mechanism by which correctors rescue the trafficking mutant of cystic fibrosis transmembrane conductance regulator (CFTR). We transfected COS-7 cells with ΔF508, created HEK-293 stably expressing ΔF508, and utilized CFBE41o(-) cell lines stably transduced with ΔF508. As shown previously, ΔF508 expressed less protein, was unstable at physiological temperature, and rapidly degraded. When the cells were treated with the combination C18 + C4 the mature C-band was expressed at the cell surface. After treatment with C18 + C4, we saw a lower rate of protein disappearance after translation was stopped with cycloheximide. To understand how this rescue occurs, we evaluated the change in the binding of proteins involved in endoplasmic reticulum-associated degradation, such as Hsp27 (HspB1) and Hsp40 (DnaJ). We saw a dramatic reduction in binding to heat shock proteins 27 and 40 following combined corrector therapy. siRNA experiments confirmed that a reduction in Hsp27 or Hsp40 rescued CFTR in the ΔF508 mutant, but the rescue was not additive or synergistic with C4 + 18 treatment, indicating these correctors shared a common pathway for rescue involving a network of endoplasmic reticulum-associated degradation proteins.
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Affiliation(s)
- Miquéias Lopes-Pacheco
- From the Departments of Medicine and Physiology, Johns Hopkins University, Baltimore, Maryland 21205 and the Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Clément Boinot
- From the Departments of Medicine and Physiology, Johns Hopkins University, Baltimore, Maryland 21205 and
| | - Inna Sabirzhanova
- From the Departments of Medicine and Physiology, Johns Hopkins University, Baltimore, Maryland 21205 and
| | - Marcelo M Morales
- the Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - William B Guggino
- From the Departments of Medicine and Physiology, Johns Hopkins University, Baltimore, Maryland 21205 and
| | - Liudmila Cebotaru
- From the Departments of Medicine and Physiology, Johns Hopkins University, Baltimore, Maryland 21205 and
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160
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The search for a common structural moiety among selected pharmacological correctors of the mutant CFTR chloride channel. Future Med Chem 2015; 6:1857-68. [PMID: 25495980 DOI: 10.4155/fmc.14.118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The F508del mutation impairs the trafficking of CFTR from endoplasmic reticulum to plasma membrane and is responsible of a severe form of cystic fibrosis. Trafficking can be improved by small organic molecules called 'correctors'. MATERIALS & METHODS By different synthetic ways, we prepared 4-chloroanisole and 2-(4-chloroanisol-2-yl)aminothiazole derivatives. Such compounds were ineffective as correctors but we could find a sign of activity in an intermediate. In the meantime, we found a common pharmacophoric moiety present in four known correctors. RESULTS Following this structural indication, we synthesized a small set of new molecules endowed with a significant, even if not great, F508del-CFTR rescue activity. CONCLUSION The cited structural feature seems interesting in the search of new correctors. To corroborate this observation, later on we found a new pyrazine derivative (Novartis) endowed with a potent activity as corrector and having the cited common design.
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161
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Sinha C, Zhang W, Moon CS, Actis M, Yarlagadda S, Arora K, Woodroofe K, Clancy JP, Lin S, Ziady AG, Frizzell R, Fujii N, Naren AP. Capturing the Direct Binding of CFTR Correctors to CFTR by Using Click Chemistry. Chembiochem 2015; 16:2017-22. [PMID: 26227551 DOI: 10.1002/cbic.201500123] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Indexed: 12/26/2022]
Abstract
Cystic fibrosis (CF) is a lethal genetic disease caused by the loss or dysfunction of the CF transmembrane conductance regulator (CFTR) channel. F508del is the most prevalent mutation of the CFTR gene and encodes a protein defective in folding and processing. VX-809 has been reported to facilitate the folding and trafficking of F508del-CFTR and augment its channel function. The mechanism of action of VX-809 has been poorly understood. In this study, we sought to answer a fundamental question underlying the mechanism of VX-809: does it bind CFTR directly in order to exert its action? We synthesized two VX-809 derivatives, ALK-809 and SUL-809, that possess an alkyne group and retain the rescue capacity of VX-809. By using Cu(I) -catalyzed click chemistry, we provide evidence that the VX-809 derivatives bind CFTR directly in vitro and in cells. Our findings will contribute to the elucidation of the mechanism of action of CFTR correctors and the design of more potent therapeutics to combat CF.
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Affiliation(s)
- Chandrima Sinha
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA.,Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Weiqiang Zhang
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, 38163, USA.,Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, 38103, USA
| | - Chang Suk Moon
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Marcelo Actis
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Sunitha Yarlagadda
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Kavisha Arora
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Koryse Woodroofe
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - John P Clancy
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Songbai Lin
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Assem G Ziady
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Raymond Frizzell
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA
| | - Naoaki Fujii
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Anjaparavanda P Naren
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA. .,Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, 38163, USA.
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162
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Guglani L. Changing the Paradigm - Treating the Basic Defect in Cystic Fibrosis. Indian J Pediatr 2015; 82:727-36. [PMID: 26077199 DOI: 10.1007/s12098-015-1786-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 05/05/2015] [Indexed: 11/28/2022]
Abstract
Since the first description of Cystic fibrosis (CF) more than 75 y ago, significant advances have been made in understanding its pathogenesis and in developing specific therapies. The pace of these developments was further accelerated after the discovery of CF gene in 1989 and since then, CF has been transformed from being a pediatric illness into a chronic life-limiting genetic disorder with survival up to the fourth decade. The development of mutation-specific therapies in the first decade of the 21st century has the potential to change the natural history of CF and has now ushered in the era of 'Precision Medicine'. The ability to revert the basic defect in CF by using Personalized Medicine approach based on each individual's genetic profile will serve as a model for other chronic disorders as well. This review highlights the recent advances in the field of CF research that have led to a paradigm shift in its management and outcomes.
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Affiliation(s)
- Lokesh Guglani
- Division of Pulmonary Medicine, Department of Pediatrics, Children's Hospital of Michigan, Wayne State University School of Medicine, 3901 Beaubien St, Detroit, MI, 48201, USA,
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163
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Norez C, Vandebrouck C, Bertrand J, Noel S, Durieu E, Oumata N, Galons H, Antigny F, Chatelier A, Bois P, Meijer L, Becq F. Roscovitine is a proteostasis regulator that corrects the trafficking defect of F508del-CFTR by a CDK-independent mechanism. Br J Pharmacol 2015; 171:4831-49. [PMID: 25065395 DOI: 10.1111/bph.12859] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 03/07/2014] [Accepted: 04/10/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE The most common mutation in cystic fibrosis (CF), F508del, causes defects in trafficking, channel gating and endocytosis of the CF transmembrane conductance regulator (CFTR) protein. Because CF is an orphan disease, therapeutic strategies aimed at improving mutant CFTR functions are needed to target the root cause of CF. EXPERIMENTAL APPROACH Human CF airway epithelial cells were treated with roscovitine 100 μM for 2 h before CFTR maturation, expression and activity were examined. The mechanism of action of roscovitine was explored by recording the effect of depleting endoplasmic reticulum (ER) Ca(2+) on the F508del-CFTR/calnexin interaction and by measuring proteasome activity. KEY RESULTS Of the cyclin-dependent kinase (CDK) inhibitors investigated, roscovitine was found to restore the cell surface expression and defective channel function of F508del-CFTR in human CF airway epithelial cells. Neither olomoucine nor (S)-CR8, two very efficient CDK inhibitors, corrected F508del-CFTR trafficking demonstrating that the correcting effect of roscovitine was independent of CDK inhibition. Competition studies with inhibitors of the ER quality control (ERQC) indicated that roscovitine acts on the calnexin pathway and on the degradation machinery. Roscovitine was shown (i) to partially inhibit the interaction between F508del-CFTR and calnexin by depleting ER Ca(2+) and (ii) to directly inhibit the proteasome activity in a Ca(2+) -independent manner. CONCLUSIONS AND IMPLICATIONS Roscovitine is able to correct the defective function of F508del-CFTR by preventing the ability of the ERQC to interact with and degrade F508del-CFTR via two synergistic but CDK-independent mechanisms. Roscovitine has potential as a pharmacological therapy for CF.
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Affiliation(s)
- C Norez
- Institut de Physiologie et Biologie Cellulaires, Université de Poitiers, Poitiers, France
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Sabirzhanova I, Lopes Pacheco M, Rapino D, Grover R, Handa JT, Guggino WB, Cebotaru L. Rescuing Trafficking Mutants of the ATP-binding Cassette Protein, ABCA4, with Small Molecule Correctors as a Treatment for Stargardt Eye Disease. J Biol Chem 2015; 290:19743-55. [PMID: 26092729 DOI: 10.1074/jbc.m115.647685] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Indexed: 11/06/2022] Open
Abstract
Stargardt disease is the most common form of early onset macular degeneration. Mutations in ABCA4, a member of the ATP-binding cassette (ABC) family, are associated with Stargardt disease. Here, we have examined two disease-causing mutations in the NBD1 region of ABCA4, R1108C, and R1129C, which occur within regions of high similarity with CFTR, another ABC transporter gene, which is associated with cystic fibrosis. We show that R1108C and R1129C are both temperature-sensitive processing mutants that engage the cellular quality control mechanism and show a strong interaction with the chaperone Hsp 27. Both mutant proteins also interact with HDCAC6 and are degraded in the aggresome. We also demonstrate that novel corrector compounds that are being tested as treatment for cystic fibrosis, such as VX-809, can rescue the processing of the ABCA4 mutants, particularly their expression at the cell surface, and can reduce their binding to HDAC6. Thus, our data suggest that VX-809 can potentially be developed as a new therapy for Stargardt disease, for which there is currently no treatment.
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Affiliation(s)
- Inna Sabirzhanova
- From the Division of Gastroenterology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, Physiology Center for Retinal Biology, and
| | - Miquéias Lopes Pacheco
- From the Division of Gastroenterology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, Physiology Center for Retinal Biology, and
| | - Daniele Rapino
- From the Division of Gastroenterology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, Physiology Center for Retinal Biology, and
| | - Rahul Grover
- From the Division of Gastroenterology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, Physiology Center for Retinal Biology, and
| | - James T Handa
- Department of Ophthalmology, Johns Hopkins University, Baltimore, Maryland 21231
| | - William B Guggino
- From the Division of Gastroenterology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21205
| | - Liudmila Cebotaru
- From the Division of Gastroenterology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, Physiology Center for Retinal Biology, and Department of Ophthalmology, Johns Hopkins University, Baltimore, Maryland 21231
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165
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Cheng D, Weckerle A, Yu Y, Ma L, Zhu X, Murea M, Freedman BI, Parks JS, Shelness GS. Biogenesis and cytotoxicity of APOL1 renal risk variant proteins in hepatocytes and hepatoma cells. J Lipid Res 2015; 56:1583-93. [PMID: 26089538 DOI: 10.1194/jlr.m059733] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Indexed: 12/21/2022] Open
Abstract
Two APOL1 gene variants, which likely evolved to protect individuals from African sleeping sickness, are strongly associated with nondiabetic kidney disease in individuals with recent African ancestry. Consistent with its role in trypanosome killing, the pro-death APOL1 protein is toxic to most cells, but its mechanism of cell death is poorly understood and little is known regarding its intracellular trafficking and secretion. Because the liver appears to be the main source of circulating APOL1, we examined its secretory behavior and mechanism of toxicity in hepatoma cells and primary human hepatocytes. APOL1 is poorly secreted in vitro, even in the presence of chemical chaper-ones; however, it is efficiently secreted in wild-type transgenic mice, suggesting that APOL1 secretion has specialized requirements that cultured cells fail to support. In hepatoma cells, inducible expression of APOL1 and its risk variants promoted cell death, with the G1 variant displaying the highest degree of toxicity. To explore the basis for APOL1-mediated cell toxicity, endoplasmic reticulum stress, pyroptosis, autophagy, and apoptosis were examined. Our results suggest that autophagy represents the predominant mechanism of APOL1-mediated cell death. Overall, these results increase our understanding of the basic biology and trafficking behavior of circulating APOL1 from the liver.
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Affiliation(s)
- Dongmei Cheng
- Department of Internal Medicine, Sections on Molecular Medicine Wake Forest School of Medicine, Winston-Salem, NC
| | - Allison Weckerle
- Department of Internal Medicine, Sections on Molecular Medicine Wake Forest School of Medicine, Winston-Salem, NC
| | - Yi Yu
- Department of Internal Medicine, Sections on Molecular Medicine Wake Forest School of Medicine, Winston-Salem, NC
| | - Lijun Ma
- Nephrology, Wake Forest School of Medicine, Winston-Salem, NC
| | - Xuewei Zhu
- Department of Internal Medicine, Sections on Molecular Medicine Wake Forest School of Medicine, Winston-Salem, NC
| | - Mariana Murea
- Nephrology, Wake Forest School of Medicine, Winston-Salem, NC
| | | | - John S Parks
- Department of Internal Medicine, Sections on Molecular Medicine Wake Forest School of Medicine, Winston-Salem, NC
| | - Gregory S Shelness
- Department of Internal Medicine, Sections on Molecular Medicine Wake Forest School of Medicine, Winston-Salem, NC
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166
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Sphingosine-1-Phosphate Is a Novel Regulator of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Activity. PLoS One 2015; 10:e0130313. [PMID: 26079370 PMCID: PMC4469317 DOI: 10.1371/journal.pone.0130313] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 05/18/2015] [Indexed: 01/12/2023] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) attenuates sphingosine-1-phosphate (S1P) signaling in resistance arteries and has emerged as a prominent regulator of myogenic vasoconstriction. This investigation demonstrates that S1P inhibits CFTR activity via adenosine monophosphate-activated kinase (AMPK), establishing a potential feedback link. In Baby Hamster Kidney (BHK) cells expressing wild-type human CFTR, S1P (1μmol/L) attenuates forskolin-stimulated, CFTR-dependent iodide efflux. S1P's inhibitory effect is rapid (within 30 seconds), transient and correlates with CFTR serine residue 737 (S737) phosphorylation. Both S1P receptor antagonism (4μmol/L VPC 23019) and AMPK inhibition (80μmol/L Compound C or AMPK siRNA) attenuate S1P-stimluated (i) AMPK phosphorylation, (ii) CFTR S737 phosphorylation and (iii) CFTR activity inhibition. In BHK cells expressing the ΔF508 CFTR mutant (CFTRΔF508), the most common mutation causing cystic fibrosis, both S1P receptor antagonism and AMPK inhibition enhance CFTR activity, without instigating discernable correction. In summary, we demonstrate that S1P/AMPK signaling transiently attenuates CFTR activity. Since our previous work positions CFTR as a negative S1P signaling regulator, this signaling link may positively reinforce S1P signals. This discovery has clinical ramifications for the treatment of disease states associated with enhanced S1P signaling and/or deficient CFTR activity (e.g. cystic fibrosis, heart failure). S1P receptor/AMPK inhibition could synergistically enhance the efficacy of therapeutic strategies aiming to correct aberrant CFTR trafficking.
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167
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Farinha CM, Sousa M, Canato S, Schmidt A, Uliyakina I, Amaral MD. Increased efficacy of VX-809 in different cellular systems results from an early stabilization effect of F508del-CFTR. Pharmacol Res Perspect 2015; 3:e00152. [PMID: 26171232 PMCID: PMC4492728 DOI: 10.1002/prp2.152] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 04/15/2015] [Accepted: 04/22/2015] [Indexed: 12/11/2022] Open
Abstract
Cystic fibrosis (CF), the most common recessive autosomal disease among Caucasians, is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein. The most common mutation, F508del, leads to CFTR impaired plasma membrane trafficking. Therapies modulating CFTR basic defect are emerging, such as VX-809, a corrector of F508del-CFTR traffic which just succeeded in a Phase III clinical trial. We recently showed that VX-809 is additive to two other correctors (VRT-325 and compound 4a). Here, we aimed to determine whether the differential rescuing by these compounds results from cell-specific factors or rather from distinct effects at the early biogenesis and/or processing. The rescuing efficiencies of the above three correctors were first compared in different cellular models (primary respiratory cells, cystic fibrosis bronchial epithelial and baby hamster kidney [BHK] cell lines) by functional approaches: micro-Ussing chamber and iodide efflux. Next, biochemical methods (metabolic labeling, pulse-chase and immunoprecipitation) were used to determine their impact on CFTR biogenesis / processing. Functional analyses revealed that VX-809 has the greatest rescuing efficacy and that the relative efficiencies of the three compounds are essentially maintained in all three cellular models tested. Nevertheless, biochemical data show that VX-809 significantly stabilizes F508del-CFTR immature form, an effect that is not observed for C3 nor C4. VX-809 and C3 also significantly increase accumulation of immature CFTR. Our data suggest that VX-809 increases the stability of F508del-CFTR immature form at an early phase of its biogenesis, thus explaining its increased efficacy when inducing its rescue.
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Affiliation(s)
- Carlos M Farinha
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute Campo Grande-C8, 1749-016, Lisboa, Portugal
| | - Marisa Sousa
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute Campo Grande-C8, 1749-016, Lisboa, Portugal
| | - Sara Canato
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute Campo Grande-C8, 1749-016, Lisboa, Portugal
| | - André Schmidt
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute Campo Grande-C8, 1749-016, Lisboa, Portugal
| | - Inna Uliyakina
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute Campo Grande-C8, 1749-016, Lisboa, Portugal
| | - Margarida D Amaral
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute Campo Grande-C8, 1749-016, Lisboa, Portugal
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Jeannet N, Fierz M, Schneider S, Künzi L, Baumlin N, Salathe M, Burtscher H, Geiser M. Acute toxicity of silver and carbon nanoaerosols to normal and cystic fibrosis human bronchial epithelial cells. Nanotoxicology 2015; 10:279-91. [DOI: 10.3109/17435390.2015.1049233] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Natalie Jeannet
- Institute of Anatomy, University of Bern, Bern, Switzerland,
| | - Martin Fierz
- Institute of Aerosol and Sensor Technology, University of Applied Sciences Northwestern Switzerland, Windisch, Switzerland, and
| | - Sarah Schneider
- Institute of Anatomy, University of Bern, Bern, Switzerland,
| | - Lisa Künzi
- Institute of Anatomy, University of Bern, Bern, Switzerland,
| | - Nathalie Baumlin
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, University of Miami, Miami, FL, USA
| | - Matthias Salathe
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, University of Miami, Miami, FL, USA
| | - Heinz Burtscher
- Institute of Aerosol and Sensor Technology, University of Applied Sciences Northwestern Switzerland, Windisch, Switzerland, and
| | - Marianne Geiser
- Institute of Anatomy, University of Bern, Bern, Switzerland,
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169
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Yang H, Ma T. F508del-cystic fibrosis transmembrane regulator correctors for treatment of cystic fibrosis: a patent review. Expert Opin Ther Pat 2015; 25:991-1002. [PMID: 25971311 DOI: 10.1517/13543776.2015.1045878] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
INTRODUCTION Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by malfunction of CF transmembrane regulator (CFTR). The deletion of a phenylalanine at residue 508 (F508del) is the most common mutation that causes cellular processing, chloride channel gating and protein stability defects in CFTR. Pharmacological modulators of F508del-CFTR, aimed at correcting the cellular processing defect (correctors) and the gating defect (potentiators) in CFTR protein, are regarded as promising therapeutic agents for CF disease. Endeavors in searching F508del-CFTR modulators have shown encouraging results, with several small-molecule compounds having entered clinical trials or even represented clinical options. AREAS COVERED This review covers the discovery of F508del-CFTR correctors described in both patents (2005 - present) and scientific literatures. EXPERT OPINION Cyclopropane carboxamide derivatives of CFTR correctors continue to dominate in this area, among which lumacaftor (a NBD1-MSD1/2 interface stabilizer) is the most promising compound and is now under the priority review by US FDA. However, the abrogation effect of ivacaftor (potentiator) on lumacaftor suggests the requirement of discovering new correctors and potentiators that can cooperate well. Integration screening for simultaneously identifying combinations of correctors (particularly NBD1 stabilizer) and potentiators should provide an alternative strategy. A recently reported natural product fraction library may be useful for the integration screening.
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Affiliation(s)
- Hong Yang
- a 1 School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University , Dalian 116029, P.R. China +86 411 85827085 ; +86 411 85827068 ;
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170
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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] [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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171
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Rudashevskaya EL, Stockner T, Trauner M, Freissmuth M, Chiba P. Pharmacological correction of misfolding of ABC proteins. DRUG DISCOVERY TODAY. TECHNOLOGIES 2015; 12:e87-94. [PMID: 25027379 PMCID: PMC4039138 DOI: 10.1016/j.ddtec.2014.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The endoplasmic reticulum (ER) quality control system distinguishes between correctly and incorrectly folded proteins to prevent processing of aberrantly folded conformations along the secretory pathway. Non-synonymous mutations can lead to misfolding of ABC proteins and associated disease phenotypes. Specific phenotypes may at least partially be corrected by small molecules, so-called pharmacological chaperones. Screening for folding correctors is expected to open an avenue for treatment of diseases such as cystic fibrosis and intrahepatic cholestasis.
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Affiliation(s)
- Elena L Rudashevskaya
- Institute of Medical Chemistry, Medical University of Vienna, Waehringerstrasse 10, Vienna, Austria
| | - Thomas Stockner
- Institute of Pharmacology, Medical University of Vienna, Waehringerstrasse 13, Vienna, Austria
| | - Michael Trauner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Waehringer Guertel 18-20, Austria
| | - Michael Freissmuth
- Institute of Pharmacology, Medical University of Vienna, Waehringerstrasse 13, Vienna, Austria
| | - Peter Chiba
- Institute of Medical Chemistry, Medical University of Vienna, Waehringerstrasse 10, Vienna, Austria
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172
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Trzcińska-Daneluti AM, Chen A, Nguyen L, Murchie R, Jiang C, Moffat J, Pelletier L, Rotin D. RNA Interference Screen to Identify Kinases That Suppress Rescue of ΔF508-CFTR. Mol Cell Proteomics 2015; 14:1569-83. [PMID: 25825526 DOI: 10.1074/mcp.m114.046375] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Indexed: 01/08/2023] Open
Abstract
Cystic Fibrosis (CF) is an autosomal recessive disorder caused by mutations in the gene encoding the Cystic fibrosis transmembrane conductance regulator (CFTR). ΔF508-CFTR, the most common disease-causing CF mutant, exhibits folding and trafficking defects and is retained in the endoplasmic reticulum, where it is targeted for proteasomal degradation. To identify signaling pathways involved in ΔF508-CFTR rescue, we screened a library of endoribonuclease-prepared short interfering RNAs (esiRNAs) that target ∼750 different kinases and associated signaling proteins. We identified 20 novel suppressors of ΔF508-CFTR maturation, including the FGFR1. These were subsequently validated by measuring channel activity by the YFP halide-sensitive assay following shRNA-mediated knockdown, immunoblotting for the mature (band C) ΔF508-CFTR and measuring the amount of surface ΔF508-CFTR by ELISA. The role of FGFR signaling on ΔF508-CFTR trafficking was further elucidated by knocking down FGFRs and their downstream signaling proteins: Erk1/2, Akt, PLCγ-1, and FRS2. Interestingly, inhibition of FGFR1 with SU5402 administered to intestinal organoids (mini-guts) generated from the ileum of ΔF508-CFTR homozygous mice resulted in a robust ΔF508-CFTR rescue. Moreover, combination of SU5402 and VX-809 treatments in cells led to an additive enhancement of ΔF508-CFTR rescue, suggesting these compounds operate by different mechanisms. Chaperone array analysis on human bronchial epithelial cells harvested from ΔF508/ΔF508-CFTR transplant patients treated with SU5402 identified altered expression of several chaperones, an effect validated by their overexpression or knockdown experiments. We propose that FGFR signaling regulates specific chaperones that control ΔF508-CFTR maturation, and suggest that FGFRs may serve as important targets for therapeutic intervention for the treatment of CF.
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Affiliation(s)
- Agata M Trzcińska-Daneluti
- From the ‡Program in Cell Biology, The Hospital for Sick Children, Toronto, and Biochemistry Department, University of Toronto; PGCRL, 19-9715, 686 Bay St., Toronto, Ont., Canada, M5G 0A4
| | - Anthony Chen
- From the ‡Program in Cell Biology, The Hospital for Sick Children, Toronto, and Biochemistry Department, University of Toronto; PGCRL, 19-9715, 686 Bay St., Toronto, Ont., Canada, M5G 0A4
| | - Leo Nguyen
- From the ‡Program in Cell Biology, The Hospital for Sick Children, Toronto, and Biochemistry Department, University of Toronto; PGCRL, 19-9715, 686 Bay St., Toronto, Ont., Canada, M5G 0A4
| | - Ryan Murchie
- From the ‡Program in Cell Biology, The Hospital for Sick Children, Toronto, and Biochemistry Department, University of Toronto; PGCRL, 19-9715, 686 Bay St., Toronto, Ont., Canada, M5G 0A4
| | - Chong Jiang
- From the ‡Program in Cell Biology, The Hospital for Sick Children, Toronto, and Biochemistry Department, University of Toronto; PGCRL, 19-9715, 686 Bay St., Toronto, Ont., Canada, M5G 0A4
| | | | | | - Daniela Rotin
- From the ‡Program in Cell Biology, The Hospital for Sick Children, Toronto, and Biochemistry Department, University of Toronto; PGCRL, 19-9715, 686 Bay St., Toronto, Ont., Canada, M5G 0A4
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173
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Rapino D, Sabirzhanova I, Lopes-Pacheco M, Grover R, Guggino WB, Cebotaru L. Rescue of NBD2 mutants N1303K and S1235R of CFTR by small-molecule correctors and transcomplementation. PLoS One 2015; 10:e0119796. [PMID: 25799511 PMCID: PMC4370480 DOI: 10.1371/journal.pone.0119796] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 01/30/2015] [Indexed: 11/18/2022] Open
Abstract
Although, the most common Cystic Fibrosis mutation, ΔF508, in the cystic fibrosis transmembrane regulator. (CFTR), is located in nucleotide binding domain (NBD1), disease-causing mutations also occur in NBD2. To provide information on potential therapeutic strategies for mutations in NBD2, we studied, using a combination of biochemical approaches and newly created cell lines, two disease-causing NBD2 mutants, N1303K and S1235R. Surprisingly, neither was rescued by low temperature. Inhibition of proteasomes with MG132 or aggresomes with tubacin rescued the immature B and mature C bands of N1303K and S1235R, indicating that degradation occurs via proteasomes and aggresomes. We found no effect of the lysosome inhibitor E64. Thus, our results show that these NBD2 mutants are processing mutants with unique characteristics. Several known correctors developed to rescue ΔF508-CFTR, when applied either alone or in combination, significantly increased the maturation of bands B and C of both NBD 2 mutants. The best correction occurred with the combinations of C4 plus C18 or C3 plus C4. Co-transfection of truncated CFTR (∆27-264) into stably transfected cells was also able to rescue them. This demonstrates for the first time that transcomplementation with a truncated version of CFTR can rescue NBD2 mutants. Our results show that the N1303K mutation has a more profound effect on NBD2 processing than S1235R and that small-molecule correctors increase the maturation of bands B and C in NBD2 mutants. In addition, ∆27-264 was able to transcomplement both NDB2 mutants. We conclude that differences and similarities occur in the impact of mutations on NBD2 when compared to ΔF508-CFTR suggesting that individualized strategies may be needed to restore their function. Finally our results are important because they suggest that gene or corrector molecule therapies either alone or in combination individualized for NBD2 mutants may be beneficial for patients bearing N1303K or S1235R mutations.
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Affiliation(s)
- Daniele Rapino
- Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Department of Physiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Inna Sabirzhanova
- Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Department of Physiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Miquéias Lopes-Pacheco
- Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Department of Physiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Rahul Grover
- Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Department of Physiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - William B. Guggino
- Department of Physiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Liudmila Cebotaru
- Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: .
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174
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Tildy BE, Rogers DF. Therapeutic options for hydrating airway mucus in cystic fibrosis. Pharmacology 2015; 95:117-32. [PMID: 25823699 DOI: 10.1159/000377638] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 02/01/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND In cystic fibrosis (CF), genetic mutations in the CF transmembrane conductance regulator (CFTR) gene cause reduced chloride efflux from ciliated airway epithelial cells. This results in a reduction in periciliary liquid (PCL) depth of the airway surface liquid due to associated reduced water efflux. PCL layer dehydration reduces mucociliary clearance (MCC), leading to airway obstruction (reduced airflow and inflammation due to pathogen invasion) with mucus plug formation. SUMMARY Rehydrating mucus increases MCC. Mucus hydration can be achieved by direct hydration (administering osmotic agents to set up an osmotic gradient), using CFTR modulators to correct dysfunctional CFTR, or it can be achieved pharmacologically (targeting other ion channels on airway epithelial cells). Key Messages: The molecular mechanisms of several therapies are discussed in the context of pre-clinical and clinical trial studies. Currently, only the osmotic agent 7% hypertonic saline and the CFTR 'potentiator' VX-770 (ivacaftor) are used clinically to hydrate mucus. Emerging therapies include the osmotic agent mannitol (Bronchitol), the intracellular Ca(2+)-raising agent Moli1901/lancovutide, the CFTR potentiator sildenafil [phosphodiesterase type 5 (PDE5) inhibitor] and the CFTR 'corrector' VX-809 (lumacaftor). Other CFTR correctors (e.g. 'chemical chaperones') are also showing pre-clinical promise.
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175
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Trinh NTN, Bilodeau C, Maillé É, Ruffin M, Quintal MC, Desrosiers MY, Rousseau S, Brochiero E. Deleterious impact of Pseudomonas aeruginosa on cystic fibrosis transmembrane conductance regulator function and rescue in airway epithelial cells. Eur Respir J 2015; 45:1590-602. [PMID: 25792634 DOI: 10.1183/09031936.00076214] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 12/28/2014] [Indexed: 11/05/2022]
Abstract
The epithelial response to bacterial airway infection, a common feature of lung diseases such as chronic obstructive pulmonary disease and cystic fibrosis, has been extensively studied. However, its impact on cystic fibrosis transmembrane conductance regulator (CFTR) channel function is not clearly defined. Our aims were, therefore, to evaluate the effect of Pseudomonas aeruginosa on CFTR function and expression in non-cystic fibrosis airway epithelial cells, and to investigate its impact on ΔF508-CFTR rescue by the VRT-325 corrector in cystic fibrosis cells. CFTR expression/maturation was evaluated by immunoblotting and its function by short-circuit current measurements. A 24-h exposure to P. aeruginosa diffusible material (PsaDM) reduced CFTR currents as well as total and membrane protein expression of the wildtype (wt) CFTR protein in CFBE-wt cells. In CFBE-ΔF508 cells, PsaDM severely reduced CFTR maturation and current rescue induced by VRT-325. We also confirmed a deleterious impact of PsaDM on wt-CFTR currents in non-cystic fibrosis primary airway cells as well as on the rescue of ΔF508-CFTR function induced by VRT-325 in primary cystic fibrosis cells. These findings show that CFTR function could be impaired in non-cystic fibrosis patients infected by P. aeruginosa. Our data also suggest that CFTR corrector efficiency may be affected by infectious components, which should be taken into account in screening assays of correctors.
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Affiliation(s)
- Nguyen Thu Ngan Trinh
- Centre de Recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada Dept de médecine, Université de Montréal, Montréal, QC, Canada Both authors contributed equally
| | - Claudia Bilodeau
- Centre de Recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada Dept de médecine, Université de Montréal, Montréal, QC, Canada Both authors contributed equally
| | - Émilie Maillé
- Centre de Recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Manon Ruffin
- Centre de Recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada Dept de médecine, Université de Montréal, Montréal, QC, Canada
| | - Marie-Claude Quintal
- Paediatric Otolaryngology Service, Centre Hospitalier Universitaire Sainte-Justine, Montréal, QC, Canada
| | - Martin-Yvon Desrosiers
- Centre de Recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Simon Rousseau
- Meakins-Christie Laboratories, Dept of Medicine, McGill University, Montréal, QC, Canada
| | - Emmanuelle Brochiero
- Centre de Recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada Dept de médecine, Université de Montréal, Montréal, QC, Canada
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176
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Shah K, Cheng Y, Hahn B, Bridges R, Bradbury NA, Mueller DM. Synonymous codon usage affects the expression of wild type and F508del CFTR. J Mol Biol 2015; 427:1464-1479. [PMID: 25676312 DOI: 10.1016/j.jmb.2015.02.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/03/2015] [Accepted: 02/04/2015] [Indexed: 10/24/2022]
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel composed of 1480 amino acids. The major mutation responsible for cystic fibrosis results in loss of amino acid residue, F508 (F508del). Loss of F508 in CFTR alters the folding pathway resulting in endoplasmic-reticulum-associated degradation. This study investigates the role of synonymous codon in the expression of CFTR and CFTR F508del in human HEK293 cells. DNA encoding the open reading frame (ORF) for CFTR containing synonymous codon replacements was expressed using a heterologous vector integrated into the genome. The results indicate that the codon usage greatly affects the expression of CFTR. While the promoter strength driving expression of the ORFs was largely unchanged and the mRNA half-lives were unchanged, the steady-state levels of the mRNA varied by as much as 30-fold. Experiments support that this apparent inconsistency is attributed to nonsense mediated decay independent of exon junction complex. The ratio of CFTR/mRNA indicates that mRNA containing native codons was more efficient in expressing mature CFTR as compared to mRNA containing synonymous high-expression codons. However, when F508del CFTR was expressed after codon optimization, a greater percentage of the protein escaped endoplasmic-reticulum-associated degradation resulting in considerable levels of mature F508del CFTR on the plasma membrane, which showed channel activity. These results indicate that codon usage has an effect on mRNA levels and protein expression, for CFTR, and likely on chaperone-assisted folding pathway, for F508del CFTR.
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Affiliation(s)
- Kalpit Shah
- Department of Biochemistry and Molecular Biology, Rosalind Franklin University, The Chicago Medical School, North Chicago, IL 60064, USA; Department of Physiology and Biophysics, Rosalind Franklin University, The Chicago Medical School, North Chicago, IL 60064, USA
| | - Yi Cheng
- Department of Physiology and Biophysics, Rosalind Franklin University, The Chicago Medical School, North Chicago, IL 60064, USA
| | - Brian Hahn
- Department of Biochemistry and Molecular Biology, Rosalind Franklin University, The Chicago Medical School, North Chicago, IL 60064, USA
| | - Robert Bridges
- Department of Physiology and Biophysics, Rosalind Franklin University, The Chicago Medical School, North Chicago, IL 60064, USA
| | - Neil A Bradbury
- Department of Physiology and Biophysics, Rosalind Franklin University, The Chicago Medical School, North Chicago, IL 60064, USA
| | - David M Mueller
- Department of Biochemistry and Molecular Biology, Rosalind Franklin University, The Chicago Medical School, North Chicago, IL 60064, USA.
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177
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Amaral MD. Novel personalized therapies for cystic fibrosis: treating the basic defect in all patients. J Intern Med 2015; 277:155-166. [PMID: 25266997 DOI: 10.1111/joim.12314] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cystic fibrosis (CF) is the most common genetic life-shortening condition in Caucasians. Despite being a multi-organ disease, CF is classically diagnosed by symptoms of acute/chronic respiratory disease, with persistent pulmonary infections and mucus plugging of the airways and failure to thrive. These multiple symptoms originate from dysfunction of the CF transmembrane conductance regulator (CFTR) protein, a channel that mediates anion transport across epithelia. Indeed, establishment of a definite CF diagnosis requires proof of CFTR dysfunction, commonly through the so-called sweat Cl(-) test. Many drug therapies, including mucolytics and antibiotics, aim to alleviate the symptoms of CF lung disease. However, new therapies to modulate defective CFTR, the basic defect underlying CF, have started to reach the clinic, and several others are in development or in clinical trials. The novelty of these therapies is that, besides targeting the basic defect underlying CF, they are mutation specific. Indeed, even this monogenic disease is influenced by a large number of different genes and biological pathways as well as by environmental factors that are difficult to assess. Accordingly, every person with CF is unique and so functional assessment of patients' tissues ex vivo is key for diagnosing and predicting the severity of this disease. Of note, such assessment will also be crucial to assess drug responses, in order to effectively treat all CF patients. It is not because it is a monogenic disorder that personalized treatment for CF is much easier than for complex disorders.
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Affiliation(s)
- M D Amaral
- BioFIG-Center for Biodiversity, Functional and Integrative Genomics, Faculty of Sciences, University of Lisboa, Lisboa, Portugal
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178
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Sheikh S, Long F, McCoy K, Johnson T, Ryan-Wenger N, Hayes D. Ivacaftor improves appearance of sinus disease on computerised tomography in cystic fibrosis patients with G551D mutation. Clin Otolaryngol 2015; 40:16-21. [DOI: 10.1111/coa.12310] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2014] [Indexed: 11/29/2022]
Affiliation(s)
- S.I. Sheikh
- Department of Pediatrics; The Ohio State University College of Medicine; Columbus OH USA
- Section of Pulmonary Medicine; Nationwide Children's Hospital; Columbus OH USA
| | - F.R. Long
- Department of Radiology; The Ohio State University College of Medicine; Columbus OH USA
- Children's Radiological Institute; Nationwide Children's Hospital; Columbus OH USA
| | - K.S. McCoy
- Department of Pediatrics; The Ohio State University College of Medicine; Columbus OH USA
- Section of Pulmonary Medicine; Nationwide Children's Hospital; Columbus OH USA
| | - T. Johnson
- Section of Pulmonary Medicine; Nationwide Children's Hospital; Columbus OH USA
| | - N.A. Ryan-Wenger
- Department of Pediatrics; The Ohio State University College of Medicine; Columbus OH USA
- Department of Nursing Research; Nationwide Children's Hospital; Columbus OH USA
| | - D. Hayes
- Department of Pediatrics; The Ohio State University College of Medicine; Columbus OH USA
- Section of Pulmonary Medicine; Nationwide Children's Hospital; Columbus OH USA
- Department of Internal Medicine; The Ohio State University College of Medicine; Columbus OH USA
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179
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Sheikh SI, Long FR, McCoy KS, Johnson T, Ryan-Wenger NA, Hayes D. Computed tomography correlates with improvement with ivacaftor in cystic fibrosis patients with G551D mutation. J Cyst Fibros 2015; 14:84-9. [DOI: 10.1016/j.jcf.2014.06.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/29/2014] [Accepted: 06/25/2014] [Indexed: 10/25/2022]
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180
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Falguières T, Aït-Slimane T, Housset C, Maurice M. ABCB4: Insights from pathobiology into therapy. Clin Res Hepatol Gastroenterol 2014; 38:557-63. [PMID: 24953525 DOI: 10.1016/j.clinre.2014.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 02/25/2014] [Accepted: 03/05/2014] [Indexed: 02/04/2023]
Abstract
Adenosine triphosphate (ATP)-binding cassette, sub-family B, member 4 (ABCB4), also called multidrug resistance 3 (MDR3), is a member of the ATP-binding cassette transporter superfamily, which is localized at the canalicular membrane of hepatocytes, and mediates the translocation of phosphatidylcholine into bile. Phosphatidylcholine secretion is crucial to ensure solubilization of cholesterol into mixed micelles and to prevent bile acid toxicity towards hepatobiliary epithelia. Genetic defects of ABCB4 may cause progressive familial intrahepatic cholestasis type 3 (PFIC3), a rare autosomic recessive disease occurring early in childhood that may be lethal in the absence of liver transplantation, and other cholestatic or cholelithiasic diseases in heterozygous adults. Development of therapies for these conditions requires understanding of the biology of this transporter and how gene variations may cause disease. This review focuses on our current knowledge on the regulation of ABCB4 expression, trafficking and function, and presents recent advances in fundamental research with promising therapeutic perspectives.
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Affiliation(s)
- Thomas Falguières
- INSERM, UMR_S 938, CDR Saint-Antoine, 75012 Paris, France; UMR_S 938, CDR Saint-Antoine, Sorbonne Universités, UPMC - Université Paris-06, 75012 Paris, France
| | - Tounsia Aït-Slimane
- INSERM, UMR_S 938, CDR Saint-Antoine, 75012 Paris, France; UMR_S 938, CDR Saint-Antoine, Sorbonne Universités, UPMC - Université Paris-06, 75012 Paris, France
| | - Chantal Housset
- INSERM, UMR_S 938, CDR Saint-Antoine, 75012 Paris, France; UMR_S 938, CDR Saint-Antoine, Sorbonne Universités, UPMC - Université Paris-06, 75012 Paris, France; Service d'hépatologie, Centre Maladies Rares (CMR) Maladies Inflammatoires des Voies Biliaires, Hôpital Saint-Antoine, Assistance publique-Hôpitaux de Paris, 75012 Paris, France
| | - Michèle Maurice
- INSERM, UMR_S 938, CDR Saint-Antoine, 75012 Paris, France; UMR_S 938, CDR Saint-Antoine, Sorbonne Universités, UPMC - Université Paris-06, 75012 Paris, France.
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181
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Monterisi S, Casavola V, Zaccolo M. Local modulation of cystic fibrosis conductance regulator: cytoskeleton and compartmentalized cAMP signalling. Br J Pharmacol 2014; 169:1-9. [PMID: 23072488 DOI: 10.1111/bph.12017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 09/12/2012] [Accepted: 10/05/2012] [Indexed: 11/28/2022] Open
Abstract
The cystic fibrosis conductance regulator (CFTR) is a cAMP-regulated Cl(-) channel expressed predominantly at the apical membrane of secreting epithelial cells. Mutations in the CFTR gene lead to cystic fibrosis, the most frequent genetic disease in the Caucasian population. The most common mutation, a deletion of phenylalanine at position 508 (F508del), impairs CFTR folding and chloride channel function. Although an intense effort is under way to identify compounds that target the F508del CFTR structural defect and promote its expression and stability at the plasma membrane, so far their clinical efficacy has proven to be poor, highlighting the necessity to better understand the molecular mechanism of CFTR regulation and of the pathogenesis of the disease. Accumulating evidence suggests that the inclusion of the CFTR in macromolecular complexes and its interaction with the cortical cytoskeleton may play a key role in fine-tuning the regulation of channel function. Here we review some recent findings that support a critical role for protein-protein interactions involving CFTR and for the cytoskeleton in promoting local control of channel activity. These findings indicate that compounds that rescue and stabilize CFTR at the apical membrane may not be sufficient to restore its function unless the appropriate intracellular milieu is also reconstituted.
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Affiliation(s)
- Stefania Monterisi
- Department of Physiology, Anatomy and Genetics, Oxford University, Oxford, UK
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182
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Liu X, Dawson DC. Cystic fibrosis transmembrane conductance regulator (CFTR) potentiators protect G551D but not ΔF508 CFTR from thermal instability. Biochemistry 2014; 53:5613-8. [PMID: 25148434 PMCID: PMC4159205 DOI: 10.1021/bi501007v] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
![]()
The G551D cystic fibrosis transmembrane
conductance regulator (CFTR)
mutation is associated with severe disease in ∼5% of cystic
fibrosis patients worldwide. This amino acid substitution in NBD1
results in a CFTR chloride channel characterized by a severe gating
defect that can be at least partially overcome in vitro by exposure to a CFTR potentiator. In contrast, the more common
ΔF508 mutation is associated with a severe protein trafficking
defect, as well as impaired channel function. Recent clinical trials
demonstrated a beneficial effect of the CFTR potentiator, Ivacaftor
(VX-770), on lung function of patients bearing at least one copy of
G551D CFTR, but no comparable effect on ΔF508 homozygotes. This
difference in efficacy was not surprising in view of the established
difference in the molecular phenotypes of the two mutant channels.
Recently, however, it was shown that the structural defect introduced
by the deletion of F508 is associated with the thermal instability
of ΔF508 CFTR channel function in vitro. This
additional mutant phenotype raised the possibility that the differences
in the behavior of ΔF508 and G551D CFTR, as well as the disparate
efficacy of Ivacaftor, might be a reflection of the differing thermal
stabilities of the two channels at 37 °C. We compared the thermal
stability of G551D and ΔF508 CFTR in Xenopus oocytes in the presence and absence of CTFR potentiators. G551D
CFTR exhibited a thermal instability that was comparable to that of
ΔF508 CFTR. G551D CFTR, however, was protected from thermal
instability by CFTR potentiators, whereas ΔF508 CFTR was not.
These results suggest that the efficacy of VX-770 in patients bearing
the G551D mutation is due, at least in part, to the ability of the
small molecule to protect the mutant channel from thermal instability
at human body temperature.
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Affiliation(s)
- Xuehong Liu
- Department of Physiology & Pharmacology, Oregon Health & Science University , Portland, Oregon 97239, United States
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183
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184
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He L, Aleksandrov AA, An J, Cui L, Yang Z, Brouillette CG, Riordan JR. Restoration of NBD1 thermal stability is necessary and sufficient to correct ∆F508 CFTR folding and assembly. J Mol Biol 2014; 427:106-20. [PMID: 25083918 DOI: 10.1016/j.jmb.2014.07.026] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/09/2014] [Accepted: 07/11/2014] [Indexed: 11/29/2022]
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) (ABCC7), unique among ABC exporters as an ion channel, regulates ion and fluid transport in epithelial tissues. Loss of function due to mutations in the cftr gene causes cystic fibrosis. The most common cystic-fibrosis-causing mutation, the deletion of F508 (ΔF508) from the first nucleotide binding domain (NBD1) of CFTR, results in misfolding of the protein and clearance by cellular quality control systems. The ΔF508 mutation has two major impacts on CFTR: reduced thermal stability of NBD1 and disruption of its interface with membrane-spanning domains (MSDs). It is unknown if these two defects are independent and need to be targeted separately. To address this question, we varied the extent of stabilization of NBD1 using different second-site mutations and NBD1 binding small molecules with or without NBD1/MSD interface mutation. Combinations of different NBD1 changes had additive corrective effects on ∆F508 maturation that correlated with their ability to increase NBD1 thermostability. These effects were much larger than those caused by interface modification alone and accounted for most of the correction achieved by modifying both the domain and the interface. Thus, NBD1 stabilization plays a dominant role in overcoming the ΔF508 defect. Furthermore, the dual target approach resulted in a locked-open ion channel that was constitutively active in the absence of the normally obligatory dependence on phosphorylation by protein kinase A. Thus, simultaneous targeting of both the domain and the interface, as well as being non-essential for correction of biogenesis, may disrupt normal regulation of channel function.
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Affiliation(s)
- Lihua He
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Andrei A Aleksandrov
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Jianli An
- Center for Structural Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Liying Cui
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Zhengrong Yang
- Center for Structural Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA; Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Christie G Brouillette
- Center for Structural Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA; Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - John R Riordan
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC, 27599, USA.
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185
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Collawn JF, Fu L, Bartoszewski R, Matalon S. Rescuing ΔF508 CFTR with trimethylangelicin, a dual-acting corrector and potentiator. Am J Physiol Lung Cell Mol Physiol 2014; 307:L431-4. [PMID: 25063802 DOI: 10.1152/ajplung.00177.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Since the discovery of the cystic fibrosis (CF) gene that encodes the CF transmembrane conductance regulator (CFTR) in 1989, there has been considerable progress in understanding the molecular defects associated with different mutations in the CFTR protein. Small molecule "potentiators" have led the way as a drug therapeutic approach for correcting channel gating mutations such as the G551D mutation. Therapies for correcting the most common folding mutation in CFTR, ΔF508, however, have proven to be much more challenging. The protein-folding problem appears to be associated with both nucleotide binding domain (NBD) instability and domain interface interactions that are caused by the loss of the phenylalanine residue in NBD 1. Given the inherent complexity in the sequential folding pathway for this very large multidomain protein, it has been suggested that correcting the proper folding, anion channel function, and cell surface stability of the ΔF508 CFTR protein will require a multidrug approach to fix each of these compounding problems. Here we discuss a recent publication (Favia M, Mancini MT, Bezzerri V, Guerra L, Laselva O, Abbattiscianni AC, Debellis L, Reshkin SJ, Gambari R, Cabrini G, Casavola V. Am J Physiol Lung Cell Mol Physiol 307: L48-L61, 2014), however, that offers hope that single drug therapies are still possible.
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Affiliation(s)
- James F Collawn
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama; Pulmonary Injury and Repair Center, University of Alabama at Birmingham, Birmingham, Alabama; Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Lianwu Fu
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama; Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Rafal Bartoszewski
- Department of Biology and Pharmaceutical Botany, Medical University of Gdansk, Gdansk, Poland
| | - Sadis Matalon
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama; Department of Anesthesiology, University of Alabama at Birmingham, Birmingham, Alabama; Pulmonary Injury and Repair Center, University of Alabama at Birmingham, Birmingham, Alabama; Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama; and
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186
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Genetics of cystic fibrosis: CFTR mutation classifications toward genotype-based CF therapies. Int J Biochem Cell Biol 2014; 52:94-102. [DOI: 10.1016/j.biocel.2014.02.023] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/24/2014] [Accepted: 02/28/2014] [Indexed: 12/17/2022]
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187
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Pranke IM, Sermet-Gaudelus I. Biosynthesis of cystic fibrosis transmembrane conductance regulator. Int J Biochem Cell Biol 2014; 52:26-38. [DOI: 10.1016/j.biocel.2014.03.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 03/19/2014] [Accepted: 03/20/2014] [Indexed: 01/19/2023]
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188
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Carlile GW, Robert R, Goepp J, Matthes E, Liao J, Kus B, Macknight SD, Rotin D, Hanrahan JW, Thomas DY. Ibuprofen rescues mutant cystic fibrosis transmembrane conductance regulator trafficking. J Cyst Fibros 2014; 14:16-25. [PMID: 24974227 DOI: 10.1016/j.jcf.2014.06.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 05/27/2014] [Accepted: 06/01/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND Small molecules as shown by VX809 can rescue the mislocalization of F508del-CFTR. The aim of this study was to identify correctors with a clinical history and their targets of action. METHODS CFTR correctors were screened using two F508del-CFTR expressing cell based HTS assays. Electrophysiological studies using CFBE41o(-) and HBE cells and in-vivo mouse assays confirmed CFTR rescue. The target of action was attained using pharmacological inhibitors and siRNA to specific genes. RESULTS Ibuprofen was identified as a CFTR corrector. Ibuprofen treatment of polarized CFBE41o(-) monolayers increased the short-circuit current (Isc) response to stimulation. In vivo CF mice treatment with ibuprofen restored the CFTR trafficking. SiRNA knock down of cyclooxygenase expression caused partial F508del-CFTR correction. CONCLUSION These studies show that ibuprofen is a CFTR corrector and that it causes correction by COX-1 inhibition. Hence ibuprofen may be suitable to be part of a future CF combination therapy.
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Affiliation(s)
- Graeme W Carlile
- Cystic Fibrosis Translational Research Center, Dept. of Biochemistry, McGill University, Montreal, Quebec H3G1Y6, Canada.
| | - Renaud Robert
- Cystic Fibrosis Translational Research Center, Dept. of Physiology, McGill University, Montreal, Quebec H3G1Y6, Canada
| | - Julie Goepp
- Cystic Fibrosis Translational Research Center, Dept. of Physiology, McGill University, Montreal, Quebec H3G1Y6, Canada
| | - Elizabeth Matthes
- Cystic Fibrosis Translational Research Center, Dept. of Physiology, McGill University, Montreal, Quebec H3G1Y6, Canada
| | - Jie Liao
- Cystic Fibrosis Translational Research Center, Dept. of Physiology, McGill University, Montreal, Quebec H3G1Y6, Canada
| | - Bart Kus
- Hospital for Sick Children, Dept. of Biochemistry, University of Toronto, Ontario M5G 1X8, Canada
| | - Sean D Macknight
- Cystic Fibrosis Translational Research Center, Dept. of Biochemistry, McGill University, Montreal, Quebec H3G1Y6, Canada
| | - Daniela Rotin
- Hospital for Sick Children, Dept. of Biochemistry, University of Toronto, Ontario M5G 1X8, Canada
| | - John W Hanrahan
- Cystic Fibrosis Translational Research Center, Dept. of Physiology, McGill University, Montreal, Quebec H3G1Y6, Canada
| | - David Y Thomas
- Cystic Fibrosis Translational Research Center, Dept. of Biochemistry, McGill University, Montreal, Quebec H3G1Y6, Canada
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189
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Abstract
Cystic fibrosis (CF) remains the most common fatal hereditary lung disease. The discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene 25 years ago set the stage for: 1) unravelling the molecular and cellular basis of CF lung disease; 2) the generation of animal models to study in vivo pathogenesis; and 3) the development of mutation-specific therapies that are now becoming available for a subgroup of patients with CF. This article highlights major advances in our understanding of how CFTR dysfunction causes chronic mucus obstruction, neutrophilic inflammation and bacterial infection in CF airways. Furthermore, we focus on recent breakthroughs and remaining challenges of novel therapies targeting the basic CF defect, and discuss the next steps to be taken to make disease-modifying therapies available to a larger group of patients with CF, including those carrying the most common mutation ΔF508-CFTR. Finally, we will summarise emerging evidence indicating that acquired CFTR dysfunction may be implicated in the pathogenesis of chronic obstructive pulmonary disease, suggesting that lessons learned from CF may be applicable to common airway diseases associated with mucus plugging.
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Affiliation(s)
- Marcus A Mall
- Dept of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), University of Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany Division of Paediatric Pulmonology and Allergy and Cystic Fibrosis Center, Dept of Paediatrics, University of Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| | - Dominik Hartl
- Paediatric Infectiology and Immunology, Dept of Pediatrics, University of Tübingen, Tübingen, Germany
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190
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Favia M, Mancini MT, Bezzerri V, Guerra L, Laselva O, Abbattiscianni AC, Debellis L, Reshkin SJ, Gambari R, Cabrini G, Casavola V. Trimethylangelicin promotes the functional rescue of mutant F508del CFTR protein in cystic fibrosis airway cells. Am J Physiol Lung Cell Mol Physiol 2014; 307:L48-61. [PMID: 24816489 DOI: 10.1152/ajplung.00305.2013] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) carrying the F508del mutation is retained in endoplasmic reticulum and fails to traffic to the cell surface where it functions as a protein kinase A (PKA)-activated chloride channel. Pharmacological correctors that rescue the trafficking of F508del CFTR may overcome this defect; however, the rescued F508del CFTR still displays reduced chloride permeability. Therefore, a combined administration of correctors and potentiators of the gating defect is ideal. We recently found that 4,6,4'-trimethylangelicin (TMA), besides inhibiting the expression of the IL-8 gene in airway cells in which the inflammatory response was challenged with Pseudomonas aeruginosa, also potentiates the cAMP/PKA-dependent activation of wild-type CFTR or F508del CFTR that has been restored to the plasma membrane. Here, we demonstrate that long preincubation with nanomolar concentrations of TMA is able to effectively rescue both F508del CFTR-dependent chloride secretion and F508del CFTR cell surface expression in both primary or secondary airway cell monolayers homozygous for F508del mutation. The correction effect of TMA seems to be selective for CFTR and persisted for 24 h after washout. Altogether, the results suggest that TMA, besides its anti-inflammatory and potentiator activities, also displays corrector properties.
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Affiliation(s)
- Maria Favia
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Maria T Mancini
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Valentino Bezzerri
- Laboratory of Molecular Pathology, Department of Pathology and Diagnostics, University Hospital Verona, Verona, Italy
| | - Lorenzo Guerra
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Onofrio Laselva
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Anna C Abbattiscianni
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Lucantonio Debellis
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Stephan J Reshkin
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Roberto Gambari
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy; and
| | - Giulio Cabrini
- Laboratory of Molecular Pathology, Department of Pathology and Diagnostics, University Hospital Verona, Verona, Italy
| | - Valeria Casavola
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy; Centre of Excellence in Comparative Genomics, University of Bari, Bari, Italy
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191
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Decoding F508del misfolding in cystic fibrosis. Biomolecules 2014; 4:498-509. [PMID: 24970227 PMCID: PMC4101494 DOI: 10.3390/biom4020498] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/11/2014] [Accepted: 04/25/2014] [Indexed: 01/13/2023] Open
Abstract
The functional deficiency of the cystic fibrosis transmembrane conductance regulator (CFTR), a plasma membrane chloride channel, leads to the development of cystic fibrosis. The deletion of a phenylalanine at residue 508 (F508del) is the most common cause of CFTR misfolding leading to the disease. The F508del misfolding originates in the first nucleotide-binding domain (NBD1), which induces a global conformational change in CFTR through NBD1’s interactions with other domains. Such global misfolding produces a mutant chloride channel that is impaired in exocytic trafficking, peripheral stability, and channel gating. The nature and atomic details of F508del misfolding have been subject to extensive research during the past decade. Current data support a central role for NBD1 in F508del misfolding and rescue. Many cis-acting NBD1 second-site mutations rescue F508del misfolding in the context of full-length CFTR. While some of these mutations appear to specifically counteract the F508del-induced misfolding, others release certain inherent conformational constraints of the human wild-type CFTR. Several small-molecule correctors were recently found to act on key interdomain interfaces of F508del CFTR. Potential rational approaches have been proposed in an attempt to develop highly effective small molecule modulators that improve the cell surface functional expression of F508del CFTR.
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192
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Phuan PW, Veit G, Tan J, Roldan A, Finkbeiner WE, Lukacs GL, Verkman AS. Synergy-based small-molecule screen using a human lung epithelial cell line yields ΔF508-CFTR correctors that augment VX-809 maximal efficacy. Mol Pharmacol 2014; 86:42-51. [PMID: 24737137 DOI: 10.1124/mol.114.092478] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The most prevalent cystic fibrosis transmembrane conductance regulator (CFTR) mutation causing cystic fibrosis, ΔF508, impairs folding of nucleotide binding domain (NBD) 1 and stability of the interface between NBD1 and the membrane-spanning domains. The interfacial stability defect can be partially corrected by the investigational drug VX-809 (3-[6-[[[1-(2,2-difluoro-1,3-benzodioxol-5-yl)cyclopropyl]carbonyl]amino]-3-methyl-2-pyridinyl]-benzoic acid) or the R1070W mutation. Second-generation ΔF508-CFTR correctors are needed to improve on the modest efficacy of existing cystic fibrosis correctors. We postulated that a second corrector targeting a distinct folding/interfacial defect might act in synergy with VX-809 or the R1070W suppressor mutation. A biochemical screen for ΔF508-CFTR cell surface expression was developed in a human lung epithelium-derived cell line (CFBE41o(-)) by expressing chimeric CFTRs with a horseradish peroxidase (HRP) in the fourth exofacial loop in either the presence or absence of R1070W. Using a luminescence readout of HRP activity, screening of approximately 110,000 small molecules produced nine novel corrector scaffolds that increased cell surface ∆F508-CFTR expression by up to 200% in the presence versus absence of maximal VX-809. Further screening of 1006 analogs of compounds identified from the primary screen produced 15 correctors with an EC50 < 5 µM. Eight chemical scaffolds showed synergy with VX-809 in restoring chloride permeability in ∆F508-expressing A549 cells. An aminothiazole increased chloride conductance in human bronchial epithelial cells from a ΔF508 homozygous subject beyond that of maximal VX-809. Mechanistic studies suggested that NBD2 is required for the aminothiazole rescue. Our results provide proof of concept for synergy screening to identify second-generation correctors, which, when used in combination, may overcome the "therapeutic ceiling" of first-generation correctors.
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Affiliation(s)
- Puay-Wah Phuan
- Departments of Medicine and Physiology (P.-W.P., J.T., A.S.V.) and Department of Pathology (W.E.F.), University of California, San Francisco, California; and Groupe de Recherche Axé sur la Structure des Protéine and Departments of Physiology (G.V., A.R., G.L.L.) and Biochemistry (G.L.L.), McGill University, Montreal, Quebec, Canada
| | - Guido Veit
- Departments of Medicine and Physiology (P.-W.P., J.T., A.S.V.) and Department of Pathology (W.E.F.), University of California, San Francisco, California; and Groupe de Recherche Axé sur la Structure des Protéine and Departments of Physiology (G.V., A.R., G.L.L.) and Biochemistry (G.L.L.), McGill University, Montreal, Quebec, Canada
| | - Joseph Tan
- Departments of Medicine and Physiology (P.-W.P., J.T., A.S.V.) and Department of Pathology (W.E.F.), University of California, San Francisco, California; and Groupe de Recherche Axé sur la Structure des Protéine and Departments of Physiology (G.V., A.R., G.L.L.) and Biochemistry (G.L.L.), McGill University, Montreal, Quebec, Canada
| | - Ariel Roldan
- Departments of Medicine and Physiology (P.-W.P., J.T., A.S.V.) and Department of Pathology (W.E.F.), University of California, San Francisco, California; and Groupe de Recherche Axé sur la Structure des Protéine and Departments of Physiology (G.V., A.R., G.L.L.) and Biochemistry (G.L.L.), McGill University, Montreal, Quebec, Canada
| | - Walter E Finkbeiner
- Departments of Medicine and Physiology (P.-W.P., J.T., A.S.V.) and Department of Pathology (W.E.F.), University of California, San Francisco, California; and Groupe de Recherche Axé sur la Structure des Protéine and Departments of Physiology (G.V., A.R., G.L.L.) and Biochemistry (G.L.L.), McGill University, Montreal, Quebec, Canada
| | - Gergely L Lukacs
- Departments of Medicine and Physiology (P.-W.P., J.T., A.S.V.) and Department of Pathology (W.E.F.), University of California, San Francisco, California; and Groupe de Recherche Axé sur la Structure des Protéine and Departments of Physiology (G.V., A.R., G.L.L.) and Biochemistry (G.L.L.), McGill University, Montreal, Quebec, Canada
| | - A S Verkman
- Departments of Medicine and Physiology (P.-W.P., J.T., A.S.V.) and Department of Pathology (W.E.F.), University of California, San Francisco, California; and Groupe de Recherche Axé sur la Structure des Protéine and Departments of Physiology (G.V., A.R., G.L.L.) and Biochemistry (G.L.L.), McGill University, Montreal, Quebec, Canada
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193
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CFTR structure and cystic fibrosis. Int J Biochem Cell Biol 2014; 52:15-25. [PMID: 24534272 DOI: 10.1016/j.biocel.2014.02.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 02/04/2014] [Accepted: 02/06/2014] [Indexed: 12/31/2022]
Abstract
CFTR (cystic fibrosis transmembrane conductance regulator) is a member of the ATP-binding cassette family of membrane proteins. Although almost all members of this family are transporters, CFTR functions as a channel with specificity for anions, in particular chloride and bicarbonate. In this review we look at what is known about CFTR structure and function within the context of the ATP-binding cassette family. We also review current strategies aimed at obtaining the high resolution structure of the protein.
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Abstract
INTRODUCTION Cystic fibrosis is an autosomal recessive disease, which is the result of a genetic defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Pulmonary disease accounts for over 90% of the morbidity and mortality associated with the disease. Conventionally, CF treatment has focused on symptomatic therapy. AREAS COVERED In the past, the emphasis for the development of CF therapeutics has previously been on addressing complications of the manifestations rather than on the underlying disease process. However, in the past few decades there has been a paradigm shift with new attention on the underlying biological mechanisms and therapies targeted at curing the disease rather than simply controlling it. This review summarizes the current CF therapeutics pipeline. These developing therapies include CFTR gene therapy, CFTR pharmacotherapeutics, osmotically active agents and anti-inflammatory therapies, as well as novel inhaled antibiotics. EXPERT OPINION The CF therapeutics pipeline currently holds great promise both for novel therapies directly targeting the underlying biological mechanisms of CFTR dysfunction and new symptomatic therapies. While CFTR-directed therapy has the highest potential to improve patients' outcome, it is important to continue to develop better treatment options for all aspects of CF lung disease.
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Affiliation(s)
- Reshma Amin
- University of Toronto, The Hospital for Sick Children, Division of Respiratory Medicine, Department of Pediatrics, Physiology and Experimental Medicine , 555 University Avenue, Toronto, ON, M5G 1X8 , Canada +416 813 6346 ; +416 813 6246 ;
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195
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Cebotaru L, Rapino D, Cebotaru V, Guggino WB. Correcting the cystic fibrosis disease mutant, A455E CFTR. PLoS One 2014; 9:e85183. [PMID: 24416359 PMCID: PMC3885674 DOI: 10.1371/journal.pone.0085183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 12/03/2013] [Indexed: 11/18/2022] Open
Abstract
Cystic fibrosis is caused by more than 1000 mutations, the most common being the ΔF508 mutation. These mutations have been divided into five classes [1], with ΔF508 CFTR in class II. Here we have studied the class V mutation A455E. We report that the mature and immature bands of A455E are rapidly degraded primarily by proteasomes; the short protein half-life of this mutant therefore resembles that of ΔF508 CFTR. A455E could be rescued by treatment of the cells with proteasome inhibitors. Furthermore, co-transfection of A455E with the truncation mutant Δ264 CFTR also rescued the mature C band, indicating that A455E can be rescued by transcomplementation. We found that Δ264 CFTR bound to A455E, forming a bimolecular complex. Treatment with the compound correctors C3 and C4 also rescued A455E. These results are significant because they show that although ΔF508 belongs to a different class than A455E, it can be rescued by the same strategies, offering therapeutic promise to patients with Class V mutations.
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Affiliation(s)
- Liudmila Cebotaru
- Department of Ophthalmology, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Physiology, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Daniele Rapino
- Department of Ophthalmology, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Physiology, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Valeriu Cebotaru
- Department of Medicine, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - William B. Guggino
- Department of Physiology, School of Medicine, The Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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197
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Shah K, McCormack CE, Bradbury NA. Do you know the sex of your cells? Am J Physiol Cell Physiol 2014; 306:C3-18. [PMID: 24196532 PMCID: PMC3919971 DOI: 10.1152/ajpcell.00281.2013] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 10/31/2013] [Indexed: 11/22/2022]
Abstract
Do you know the sex of your cells? Not a question that is frequently heard around the lab bench, yet thanks to recent research is probably one that should be asked. It is self-evident that cervical epithelial cells would be derived from female tissue and prostate cells from a male subject (exemplified by HeLa and LnCaP, respectively), yet beyond these obvious examples, it would be true to say that the sex of cell lines derived from non-reproductive tissue, such as lung, intestine, kidney, for example, is given minimal if any thought. After all, what possible impact could the presence of a Y chromosome have on the biochemistry and cell biology of tissues such as the exocrine pancreatic acini? Intriguingly, recent evidence has suggested that far from being irrelevant, genes expressed on the sex chromosomes can have a marked impact on the biology of such diverse tissues as neurons and renal cells. It is also policy of AJP-Cell Physiology that the source of all cells utilized (species, sex, etc.) should be clearly indicated when submitting an article for publication, an instruction that is rarely followed (http://www.the-aps.org/mm/Publications/Info-For-Authors/Composition). In this review we discuss recent data arguing that the sex of cells being used in experiments can impact the cell's biology, and we provide a table outlining the sex of cell lines that have appeared in AJP-Cell Physiology over the past decade.
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Affiliation(s)
- Kalpit Shah
- Department of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois
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198
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Jennings MT, Riekert KA, Boyle MP. Update on key emerging challenges in cystic fibrosis. Med Princ Pract 2014; 23:393-402. [PMID: 24434297 PMCID: PMC5586905 DOI: 10.1159/000357646] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 12/01/2013] [Indexed: 12/29/2022] Open
Abstract
Cystic fibrosis (CF) is a multisystem disease causing severe chronic sinopulmonary disease and loss of pancreatic exocrine function, which affects approximately 70,000 individuals worldwide. New therapeutic developments over the last few decades have resulted in a significant increase in survival, with the median predicted survival now reaching the late thirties and more and more CF patients living well into adulthood. However, with this advent of new therapies and the associated increase in survival, new challenges in CF care have also emerged. Two of these challenges, i.e. chronic methicillin-resistant Staphylococcus aureus lung infection and patient adherence to very complicated and time-consuming therapeutic regimens, are reviewed in detail here. In addition, the ultimate challenge of treating the underlying cause of CF by correcting the dysfunction of the CF transmembrane conductance regulator chloride channel is reviewed, as agents to correct channel function will likely significantly alter CF clinical outcomes and treatment approaches in the next decade.
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Affiliation(s)
| | | | - Michael P. Boyle
- *Michael P. Boyle, MD, 1830 E. Monument Street, 5th floor, Baltimore, MD 21205 (USA), E-Mail
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Hadida S, Van Goor F, Dinehart K, Looker AR, Mueller P, Grootenhuis PD. Case History. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2014. [DOI: 10.1016/b978-0-12-800167-7.00024-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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Conger BT, Zhang S, Skinner D, Hicks SB, Sorscher EJ, Rowe SM, Woodworth BA. Comparison of cystic fibrosis transmembrane conductance regulator (CFTR) and ciliary beat frequency activation by the CFTR Modulators Genistein, VRT-532, and UCCF-152 in primary sinonasal epithelial cultures. JAMA Otolaryngol Head Neck Surg 2013; 139:822-7. [PMID: 23949358 DOI: 10.1001/jamaoto.2013.3917] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
IMPORTANCE Pharmacologic activation of mucociliary clearance (MCC) represents an emerging therapeutic strategy for patients with chronic rhinosinusitis, even in the absence of congenital mutations of the CFTR gene. Drug discovery efforts have identified small molecules that activate the cystic fibrosis transmembrane conductance regulator (CFTR), including potentiators under development for treatment of cystic fibrosis. OBJECTIVE To evaluate the properties of CFTR modulators and their effects on ciliary beat frequency (CBF) in human sinonasal epithelium (HSNE). DESIGN Primary HSNE cultures (wild type and F508del/F508del) were used to compare stimulation of CFTR-mediated Cl- conductance and CBF by the CFTR modulators genistein, VRT-532, and UCCF-152. MAIN OUTCOMES AND MEASURES Increase in CFTR-dependent anion transport and CBF. RESULTS HSNE cultures were analyzed using pharmacologic manipulation of ion transport (change in short-circuit current [∆ISC]) and high-speed digital imaging (CBF). Activation of CFTR-dependent anion transport was significantly different among agonists (P < .001), with genistein exerting the greatest effect (mean [SD] ∆ISC, genistein, 23.1 [1.8] μA/cm2² > VRT-532, 8.1 [1.0] μA/cm² > UCCF-152, 3.4 [1.4] μA/cm² > control, 0.7 [0.2] μA/cm²; Tukey-Kramer P < .05) in the absence of forskolin. Genistein and UCCF-152 augmented CBF (under submerged conditions) significantly better (Tukey-Kramer P < .05) than cells treated with VRT-532 or dimethyl sulfoxide vehicle control (mean [SD] fold change over baseline, genistein, 1.63 [0.06]; UCCF-152, 1.56 [0.06]; VRT-532, 1.38 [0.08]; control, 1.27 [0.02]). Activation of CBF was blunted in F508del/F508del HSNE cultures. CONCLUSIONS AND RELEVANCE The degree of CBF stimulation was not dependent on the magnitude of Cl- secretion, suggesting that different mechanisms of action may underlie MCC activation by these small molecule potentiators. Agents that activate both CFTR-dependent ISC and CBF are particularly attractive as therapeutics because they may address 2 independent pathways that contribute to deficient MCC in chronic rhinosinusitis.
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Affiliation(s)
- Bryant T Conger
- Division of Otolaryngology, Department of Surgery, University of Alabama at Birmingham
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