1
|
Pinto MO, Santos AS, Castanhinha S. Efficacy of elexacaftor-tezacaftor-ivacaftor in portuguese adolescents and adults with cystic fibrosis carrying non-F508del variants. Pulmonology 2024:S2531-0437(24)00041-2. [PMID: 38614858 DOI: 10.1016/j.pulmoe.2024.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/02/2024] [Accepted: 03/13/2024] [Indexed: 04/15/2024] Open
Affiliation(s)
- M O Pinto
- Cystic Fibrosis Reference Center, Santa Marta Hospital, São José Local Health Unit, Rua Santa Marta n° 50, 1169-024 Lisbon, Portugal; Department of Pulmonology, Santa Marta Hospital, São José Local Health Unit, Rua Santa Marta n° 50, 1169-024 Lisbon, Portugal.
| | - A S Santos
- Cystic Fibrosis Reference Center, Santa Marta Hospital, São José Local Health Unit, Rua Santa Marta n° 50, 1169-024 Lisbon, Portugal; Department of Pulmonology, Santa Marta Hospital, São José Local Health Unit, Rua Santa Marta n° 50, 1169-024 Lisbon, Portugal; Lung Transplantation Reference Center, Santa Marta Hospital, São José Local Health Unit, Rua Santa Marta n° 50, 1169-024 Lisbon, Portugal
| | - S Castanhinha
- Cystic Fibrosis Reference Center, Santa Marta Hospital, São José Local Health Unit, Rua Santa Marta n° 50, 1169-024 Lisbon, Portugal; Department of Pediatrics, Dona Estefânia Hospital, São José Local Health Unit, Rua Jacinta Marto n° 8A, 1169-045 Lisbon, Portugal
| |
Collapse
|
2
|
Ferreira FC, Buarque CD, Lopes-Pacheco M. Organic Synthesis and Current Understanding of the Mechanisms of CFTR Modulator Drugs Ivacaftor, Tezacaftor, and Elexacaftor. Molecules 2024; 29:821. [PMID: 38398574 PMCID: PMC10891718 DOI: 10.3390/molecules29040821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
The monogenic rare disease Cystic Fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance (CFTR) protein, an anion channel expressed at the apical plasma membrane of epithelial cells. The discovery and subsequent development of CFTR modulators-small molecules acting on the basic molecular defect in CF-have revolutionized the standard of care for people with CF (PwCF), thus drastically improving their clinical features, prognosis, and quality of life. Currently, four of these drugs are approved for clinical use: potentiator ivacaftor (VX-770) alone or in combination with correctors lumacaftor, (VX-809), tezacaftor (VX-661), and elexacaftor (VX-445). Noteworthily, the triple combinatorial therapy composed of ivacaftor, tezacaftor, and elexacaftor constitutes the most effective modulator therapy nowadays for the majority of PwCF. In this review, we exploit the organic synthesis of ivacaftor, tezacaftor, and elexacaftor by providing a retrosynthetic drug analysis for these CFTR modulators. Furthermore, we describe the current understanding of the mechanisms of action (MoA's) of these compounds by discussing several studies that report the key findings on the molecular mechanisms underlying their action on the CFTR protein.
Collapse
Affiliation(s)
- Filipa C. Ferreira
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Camilla D. Buarque
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro 22435-900, RJ, Brazil
| | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| |
Collapse
|
3
|
Li H, Rodrat M, Al-Salmani MK, Veselu DF, Han ST, Raraigh KS, Cutting GR, Sheppard DN. Two rare variants that affect the same amino acid in CFTR have distinct responses to ivacaftor. J Physiol 2024; 602:333-354. [PMID: 38186087 PMCID: PMC10872379 DOI: 10.1113/jp285727] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 12/11/2023] [Indexed: 01/09/2024] Open
Abstract
Some residues in the cystic fibrosis transmembrane conductance regulator (CFTR) channel are the site of more than one CFTR variant that cause cystic fibrosis. Here, we investigated the function of S1159F and S1159P, two variants associated with different clinical phenotypes, which affect the same pore-lining residue in transmembrane segment 12 that are both strongly potentiated by ivacaftor when expressed in CFBE41o- bronchial epithelial cells. To study the single-channel behaviour of CFTR, we applied the patch-clamp technique to Chinese hamster ovary cells heterologously expressing CFTR variants incubated at 27°C to enhance channel residence at the plasma membrane. S1159F- and S1159P-CFTR formed Cl- channels activated by cAMP-dependent phosphorylation and gated by ATP that exhibited thermostability at 37°C. Both variants modestly reduced the single-channel conductance of CFTR. By severely attenuating channel gating, S1159F- and S1159P-CFTR reduced the open probability (Po ) of wild-type CFTR by ≥75% at ATP (1 mM); S1159F-CFTR caused the greater decrease in Po consistent with its more severe clinical phenotype. Ivacaftor (10-100 nM) doubled the Po of both CFTR variants without restoring Po values to wild-type levels, but concomitantly, ivacaftor decreased current flow through open channels. For S1159F-CFTR, the reduction of current flow was marked at high (supersaturated) ivacaftor concentrations (0.5-1 μM) and voltage-independent, identifying an additional detrimental action of elevated ivacaftor concentrations. In conclusion, S1159F and S1159P are gating variants, which also affect CFTR processing and conduction, but not stability, necessitating the use of combinations of CFTR modulators to optimally restore their channel activity. KEY POINTS: Dysfunction of the ion channel cystic fibrosis transmembrane conductance regulator (CFTR) causes the genetic disease cystic fibrosis (CF). This study investigated two rare pathogenic CFTR variants, S1159F and S1159P, which affect the same amino acid in CFTR, to understand the molecular basis of disease and response to the CFTR-targeted therapy ivacaftor. Both rare variants diminished CFTR function by modestly reducing current flow through the channel and severely inhibiting ATP-dependent channel gating with S1159F exerting the stronger adverse effect, which correlates with its association with more severe disease. Ivacaftor potentiated channel gating by both rare variants without restoring their activity to wild-type levels, but concurrently reduced current flow through open channels, particularly those of S1159F-CFTR. Our data demonstrate that S1159F and S1159P cause CFTR dysfunction by multiple mechanisms that require combinations of CFTR-targeted therapies to fully restore channel function.
Collapse
Affiliation(s)
- Hongyu Li
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Mayuree Rodrat
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Center of Research and Development for Biomedical Instrumentation, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
| | - Majid K Al-Salmani
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University, Al Khoudh, Muscat, Sultanate of Oman
| | | | - Sangwoo T Han
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Karen S Raraigh
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Garry R Cutting
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - David N Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| |
Collapse
|
4
|
Yeh HI, Sutcliffe KJ, Sheppard DN, Hwang TC. CFTR Modulators: From Mechanism to Targeted Therapeutics. Handb Exp Pharmacol 2024; 283:219-247. [PMID: 35972584 DOI: 10.1007/164_2022_597] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
People with cystic fibrosis (CF) suffer from a multi-organ disorder caused by loss-of-function variants in the gene encoding the epithelial anion channel cystic fibrosis transmembrane conductance regulator (CFTR). Tremendous progress has been made in both basic and clinical sciences over the past three decades since the identification of the CFTR gene. Over 90% of people with CF now have access to therapies targeting dysfunctional CFTR. This success was made possible by numerous studies in the field that incrementally paved the way for the development of small molecules known as CFTR modulators. The advent of CFTR modulators transformed this life-threatening illness into a treatable disease by directly binding to the CFTR protein and correcting defects induced by pathogenic variants. In this chapter, we trace the trajectory of structural and functional studies that brought CF therapies from bench to bedside, with an emphasis on mechanistic understanding of CFTR modulators.
Collapse
Affiliation(s)
- Han-I Yeh
- Department of Pharmacology, National Yang Ming Chiao Tung University, Taipei City, Taiwan
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
| | - Katy J Sutcliffe
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - David N Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Tzyh-Chang Hwang
- Department of Pharmacology, National Yang Ming Chiao Tung University, Taipei City, Taiwan.
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA.
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA.
| |
Collapse
|
5
|
Liu J, Berg AP, Wang Y, Jantarajit W, Sutcliffe KJ, Stevens EB, Cao L, Pregel MJ, Sheppard DN. A small molecule CFTR potentiator restores ATP-dependent channel gating to the cystic fibrosis mutant G551D-CFTR. Br J Pharmacol 2021; 179:1319-1337. [PMID: 34644413 PMCID: PMC9304199 DOI: 10.1111/bph.15709] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 08/30/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Cystic fibrosis transmembrane conductance regulator (CFTR) potentiators are small molecules developed to treat the genetic disease cystic fibrosis (CF). They interact directly with CFTR Cl- channels at the plasma membrane to enhance channel gating. Here, we investigate the action of a new CFTR potentiator, CP-628006 with a distinct chemical structure. EXPERIMENTAL APPROACH Using electrophysiological assays with CFTR-expressing heterologous cells and CF patient-derived human bronchial epithelial (hBE) cells, we compared the effects of CP-628006 with the marketed CFTR potentiator ivacaftor. KEY RESULTS CP-628006 efficaciously potentiated CFTR function in epithelia from cultured hBE cells. Its effects on the predominant CFTR variant F508del-CFTR were larger than those with the gating variant G551D-CFTR. In excised inside-out membrane patches, CP-628006 potentiated wild-type, F508del- and G551D-CFTR by increasing the frequency and duration of channel openings. CP-628006 increased the affinity and efficacy of F508del-CFTR gating by ATP. In these respects, CP-628006 behaved like ivacaftor. CP-628006 also demonstrated notable differences with ivacaftor. Its potency and efficacy were lower than those of ivacaftor. CP-628006 conferred ATP-dependent gating on G551D-CFTR, whereas the action of ivacaftor was ATP-independent. For G551D-CFTR, but not F508del-CFTR, the action of CP-628006 plus ivacaftor was greater than ivacaftor alone. CP-628006 delayed, but did not prevent, the deactivation of F508del-CFTR at the plasma membrane, whereas ivacaftor accentuated F508del-CFTR deactivation. CONCLUSIONS AND IMPLICATIONS CP-628006 has distinct effects compared to ivacaftor, suggesting a different mechanism of CFTR potentiation. The emergence of CFTR potentiators with diverse modes of action makes therapy with combinations of potentiators a possibility.
Collapse
Affiliation(s)
- Jia Liu
- Neuroscience and Pain Research Unit, Pfizer Inc., Granta Park, Great Abington, Cambridge, UK.,School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK
| | - Allison P Berg
- Rare Disease Research Unit, Pfizer Inc., Cambridge, MA, USA
| | - Yiting Wang
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK
| | - Walailak Jantarajit
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK.,Center of Calcium and Bone Research and Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Katy J Sutcliffe
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK
| | - Edward B Stevens
- Neuroscience and Pain Research Unit, Pfizer Inc., Granta Park, Great Abington, Cambridge, UK
| | - Lishuang Cao
- Neuroscience and Pain Research Unit, Pfizer Inc., Granta Park, Great Abington, Cambridge, UK
| | - Marko J Pregel
- Rare Disease Research Unit, Pfizer Inc., Cambridge, MA, USA
| | - David N Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK
| |
Collapse
|
6
|
Yeh HI, Yu YC, Kuo PL, Tsai CK, Huang HT, Hwang TC. Functional stability of CFTR depends on tight binding of ATP at its degenerate ATP-binding site. J Physiol 2021; 599:4625-4642. [PMID: 34411298 DOI: 10.1113/jp281933] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 08/13/2021] [Indexed: 01/28/2023] Open
Abstract
Opening of the cystic fibrosis transmembrane conductance regulator (CFTR) channel is coupled to the motion of its two nucleotide-binding domains: they form a heterodimer sandwiching two functionally distinct ATP-binding sites (sites 1 and 2). While active ATP hydrolysis in site 2 triggers rapid channel closure, the functional role of stable ATP binding in the catalysis-incompetent (or degenerate) site 1, a feature conserved in many other ATP-binding cassette (ABC) transporter proteins, remains elusive. Here, we found that CFTR loses its prompt responsiveness to ATP after the channel is devoid of ATP for tens to hundreds of seconds. Mutants with weakened ATP binding in site 1 and the most prevalent disease-causing mutation, F508del, are more vulnerable to ATP depletion. In contrast, strengthening ligand binding in site 1 with N6 -(2-phenylethyl)-ATP, a high-affinity ATP analogue, or abolishing ATP hydrolysis in site 2 by the mutation D1370N, helps sustain a durable function of the otherwise unstable mutant channels. Thus, tight binding of ATP in the degenerate ATP-binding site is crucial to the functional stability of CFTR. Small molecules targeting site 1 may bear therapeutic potential to overcome the membrane instability of F508del-CFTR. KEY POINTS: During evolution, many ATP-binding cassette transporters - including the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel, whose dysfunction causes cystic fibrosis (CF) - lose the ability to hydrolyse ATP in one of the two ATP-binding sites. Here we show that tight ATP binding at this degenerate site in CFTR is central for maintaining the stable, robust function of normal CFTR. We also demonstrate that membrane instability of the most common CF-causing mutant, F508del-CFTR, can be rescued by strengthening ATP binding at CFTR's degenerate site. Our data thus explain an evolutionary puzzle and offer a potential therapeutic strategy for CF.
Collapse
Affiliation(s)
- Han-I Yeh
- Dalton Cardiovascular Research Center and Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, MO, 65211, USA.,Department of Pharmacology, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ying-Chun Yu
- Dalton Cardiovascular Research Center and Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, MO, 65211, USA
| | - Pei-Lun Kuo
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chun-Kuang Tsai
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Hsin-Tuan Huang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Tzyh-Chang Hwang
- Dalton Cardiovascular Research Center and Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, MO, 65211, USA.,Department of Pharmacology, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| |
Collapse
|
7
|
Rodrat M, Jantarajit W, Ng DRS, Harvey BSJ, Liu J, Wilkinson WJ, Charoenphandhu N, Sheppard DN. Carbon monoxide-releasing molecules inhibit the cystic fibrosis transmembrane conductance regulator Cl - channel. Am J Physiol Lung Cell Mol Physiol 2020; 319:L997-L1009. [PMID: 32936026 DOI: 10.1152/ajplung.00440.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The gasotransmitter carbon monoxide (CO) regulates fluid and electrolyte movements across epithelial tissues. However, its action on anion channels is incompletely understood. Here, we investigate the direct action of CO on the cystic fibrosis transmembrane conductance regulator (CFTR) by applying CO-releasing molecules (CO-RMs) to the intracellular side of excised inside-out membrane patches from cells heterologously expressing wild-type human CFTR. Addition of increasing concentrations of tricarbonyldichlororuthenium(II) dimer (CORM-2) (1-300 μM) inhibited CFTR channel activity, whereas the control RuCl3 (100 μM) was without effect. CORM-2 predominantly inhibited CFTR by decreasing the frequency of channel openings and, hence, open probability (Po). But, it also reduced current flow through open channels with very fast kinetics, particularly at elevated concentrations. By contrast, the chemically distinct CO-releasing molecule CORM-3 inhibited CFTR by decreasing Po without altering current flow through open channels. Neither depolarizing the membrane voltage nor raising the ATP concentration on the intracellular side of the membrane affected CFTR inhibition by CORM-2. Interestingly, CFTR inhibition by CORM-2, but not by CFTRinh-172, was prevented by prior enhancement of channel activity by the clinically approved CFTR potentiator ivacaftor. Similarly, when added after CORM-2, ivacaftor completely relieved CFTR inhibition. In conclusion, CORM-2 has complex effects on wild-type human CFTR consistent with allosteric inhibition and open-channel blockade. Inhibition of CFTR by CO-releasing molecules suggests that CO regulates CFTR activity and that the gasotransmitter has tissue-specific effects on epithelial ion transport. The action of ivacaftor on CFTR Cl- channels inhibited by CO potentially expands the drug's clinical utility.
Collapse
Affiliation(s)
- Mayuree Rodrat
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom.,Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Walailak Jantarajit
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom.,Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Demi R S Ng
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Bartholomew S J Harvey
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Jia Liu
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | | | - Narattaphol Charoenphandhu
- Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand.,Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.,The Academy of Science, The Royal Society of Thailand, Dusit, Bangkok, Thailand
| | - David N Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
8
|
Csanády L, Töröcsik B. Cystic fibrosis drug ivacaftor stimulates CFTR channels at picomolar concentrations. eLife 2019; 8:46450. [PMID: 31205003 PMCID: PMC6594753 DOI: 10.7554/elife.46450] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/14/2019] [Indexed: 02/07/2023] Open
Abstract
The devastating inherited disease cystic fibrosis (CF) is caused by mutations of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) anion channel. The recent approval of the CFTR potentiator drug ivacaftor (Vx-770) for the treatment of CF patients has marked the advent of causative CF therapy. Currently, thousands of patients are being treated with the drug, and its molecular mechanism of action is under intensive investigation. Here we determine the solubility profile and true stimulatory potency of Vx-770 towards wild-type (WT) and mutant human CFTR channels in cell-free patches of membrane. We find that its aqueous solubility is ~200 fold lower (~60 nanomolar), whereas the potency of its stimulatory effect is >100 fold higher, than reported, and is unexpectedly fully reversible. Strong, but greatly delayed, channel activation by picomolar Vx-770 identifies multiple sequential slow steps in the activation pathway. These findings provide solid guidelines for the design of in vitro studies using Vx-770.
Collapse
Affiliation(s)
- László Csanády
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary.,MTA-SE Ion Channel Research Group, Semmelweis University, Budapest, Hungary
| | - Beáta Töröcsik
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary.,MTA-SE Ion Channel Research Group, Semmelweis University, Budapest, Hungary
| |
Collapse
|
9
|
Bose SJ, Bijvelds MJC, Wang Y, Liu J, Cai Z, Bot AGM, de Jonge HR, Sheppard DN. Differential thermostability and response to cystic fibrosis transmembrane conductance regulator potentiators of human and mouse F508del-CFTR. Am J Physiol Lung Cell Mol Physiol 2019; 317:L71-L86. [PMID: 30969810 PMCID: PMC6689747 DOI: 10.1152/ajplung.00034.2019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cross-species comparative studies have highlighted differences between human and mouse cystic fibrosis transmembrane conductance regulator (CFTR), the epithelial Cl- channel defective in cystic fibrosis (CF). Here, we compare the impact of the most common CF mutation F508del on the function of human and mouse CFTR heterologously expressed in mammalian cells and their response to CFTR modulators using the iodide efflux and patch-clamp techniques. Once delivered to the plasma membrane, human F508del-CFTR exhibited a severe gating defect characterized by infrequent channel openings and was thermally unstable, deactivating within minutes at 37°C. By contrast, the F508del mutation was without effect on the gating pattern of mouse CFTR, and channel activity demonstrated thermostability at 37°C. Strikingly, at all concentrations tested, the clinically approved CFTR potentiator ivacaftor was without effect on the mouse F508del-CFTR Cl- channel. Moreover, eight CFTR potentiators, including ivacaftor, failed to generate CFTR-mediated iodide efflux from CHO cells expressing mouse F508del-CFTR. However, they all produced CFTR-mediated iodide efflux with human F508del-CFTR-expressing CHO cells, while fifteen CFTR correctors rescued the plasma membrane expression of both human and mouse F508del-CFTR. Interestingly, the CFTR potentiator genistein enhanced CFTR-mediated iodide efflux from CHO cells expressing either human or mouse F508del-CFTR, whereas it only potentiated human F508del-CFTR Cl- channels in cell-free membrane patches, suggesting that its action on mouse F508del-CFTR is indirect. Thus, the F508del mutation has distinct effects on human and mouse CFTR Cl- channels.
Collapse
Affiliation(s)
- Samuel J Bose
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol , United Kingdom
| | - Marcel J C Bijvelds
- Department of Gastroenterology and Hepatology, Erasmus University Medical Center , Rotterdam , The Netherlands
| | - Yiting Wang
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol , United Kingdom
| | - Jia Liu
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol , United Kingdom
| | - Zhiwei Cai
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol , United Kingdom
| | - Alice G M Bot
- Department of Gastroenterology and Hepatology, Erasmus University Medical Center , Rotterdam , The Netherlands
| | - Hugo R de Jonge
- Department of Gastroenterology and Hepatology, Erasmus University Medical Center , Rotterdam , The Netherlands
| | - David N Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol , United Kingdom
| |
Collapse
|
10
|
Chen X, Zhu S, Zhenin M, Xu W, Bose SJ, Wong MPF, Leung GPH, Senderowitz H, Chen JH. A defective flexible loop contributes to the processing and gating defects of the predominant cystic fibrosis-causing mutation. FASEB J 2019; 33:5126-5142. [PMID: 30668920 DOI: 10.1096/fj.201801218rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
People with the genetic disease cystic fibrosis (CF) often carry a deletion mutation ΔF508 on the gene encoding the CF transmembrane conductance regulator (CFTR) Cl- channel. This mutation greatly reduces the CFTR maturation process and slows the channel opening rate. Here, we investigate whether residues near F508 contribute to these defects in ΔF508-CFTR. Most deletion mutations, but not alanine substitutions, of individual residues from positions 503 to 513 impaired CFTR maturation. Interestingly, only protein processing of ΔY512-CFTR, like that of ΔF508-CFTR, was greatly improved by low-temperature culture at 27°C or small-molecule corrector C18. The 2 mutant Cl- channels were equally slow to open, suggesting that they may share common structural flaws. Studies on the H3-H4 loop that links residues F508 and Y512 demonstrate that G509A/V510G mutations, moving G509 1 position backward in the loop, markedly enhanced ΔF508-CFTR maturation and opening rate while promoting protein stability and persistence of the H3 helix in ΔF508 nucleotide-binding domain 1. Moreover, V510A/S511A mutations noticeably increased ΔY512-CFTR maturation at 27°C and its opening rate. Thus, loop abnormalities may contribute to ΔF508- and ΔY512-CFTR defects. Importantly, correcting defects from G509 displacement in ΔF508-CFTR may offer a new avenue for drug discovery and CF treatments.-Chen, X., Zhu, S., Zhenin, M., Xu, W., Bose, S. J., Wong, M. P.-F., Leung, G. P. H., Senderowitz, H., Chen, J.-H. A defective flexible loop contributes to the processing and gating defects of the predominant cystic fibrosis-causing mutation.
Collapse
Affiliation(s)
- Xinying Chen
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Siyu Zhu
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Michael Zhenin
- Department of Chemistry, Bar Ilan University, Ramat-Gan, Israel
| | - Weiyi Xu
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Samuel J Bose
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, United Kingdom; and
| | - Molly Pik-Fan Wong
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - George P H Leung
- Department of Pharmacology and Pharmacy, University of Hong Kong, Hong Kong, China
| | | | - Jeng-Haur Chen
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| |
Collapse
|
11
|
Wang Y, Cai Z, Gosling M, Sheppard DN. Potentiation of the cystic fibrosis transmembrane conductance regulator Cl− channel by ivacaftor is temperature independent. Am J Physiol Lung Cell Mol Physiol 2018; 315:L846-L857. [DOI: 10.1152/ajplung.00235.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Ivacaftor is the first drug to target directly defects in the cystic fibrosis transmembrane conductance regulator (CFTR), which causes cystic fibrosis (CF). To understand better how ivacaftor potentiates CFTR channel gating, here we investigated the effects of temperature on its action. As a control, we studied the benzimidazolone UCCF-853, which potentiates CFTR by a different mechanism. Using the patch-clamp technique and cells expressing recombinant CFTR, we studied the single-channel behavior of wild-type and F508del-CFTR, the most common CF mutation. Raising the temperature of the intracellular solution from 23 to 37°C increased the frequency but reduced the duration of wild-type and F508del-CFTR channel openings. Although the open probability ( Po) of wild-type CFTR increased progressively as temperature was elevated, the relationship between Po and temperature for F508del-CFTR was bell-shaped with a maximum Po at ~30°C. For wild-type CFTR and to a greatly reduced extent F508del-CFTR, the temperature dependence of channel gating was asymmetric with the opening rate demonstrating greater temperature sensitivity than the closing rate. At all temperatures tested, ivacaftor and UCCF-853 potentiated wild-type and F508del-CFTR. Strikingly, ivacaftor but not UCCF-853 abolished the asymmetric temperature dependence of CFTR channel gating. At all temperatures tested, Po values of wild-type CFTR in the presence of ivacaftor were approximately double those of F508del-CFTR, which were equivalent to or greater than those of wild-type CFTR at 37°C in the absence of the drug. We conclude that the principal effect of ivacaftor is to promote channel opening to abolish the temperature dependence of CFTR channel gating.
Collapse
Affiliation(s)
- Yiting Wang
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Zhiwei Cai
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Martin Gosling
- Enterprise Therapeutics, Sussex Innovation Centre, University of Sussex, Science Park Square, Brighton, United Kingdom
- Sussex Drug Discovery Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - David N. Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| |
Collapse
|
12
|
Lord R, Fairbourn N, Mylavarapu C, Dbeis A, Bowman T, Chandrashekar A, Banayat T, Hodges CA, Al-Nakkash L. Consuming Genistein Improves Survival Rates in the Absence of Laxative in ΔF508-CF Female Mice. Nutrients 2018; 10:E1418. [PMID: 30282922 PMCID: PMC6213472 DOI: 10.3390/nu10101418] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/11/2018] [Accepted: 09/26/2018] [Indexed: 11/16/2022] Open
Abstract
Genistein is a naturally occurring isoflavone found in soy. Genistein has been shown to increase the open probability of the most common cystic fibrosis (CF) disease-associated mutation, ∆F508-CFTR. Mice homozygous for the ∆F508 mutation are characterized with severe intestinal disease and require constant laxative treatment for survival. This pathology mimics the intestinal obstruction (meconium ileus) seen in some cystic fibrosis patients. This study tested whether dietary supplementation with genistein would reduce the dependence of the ∆F508 CF mouse model on laxatives for survival, thereby improving mortality rates. At weaning (21 days), homozygous ∆F508 mice were maintained on one of three diet regimens for a period of up to 65 days: normal diet, normal diet plus colyte, or genistein diet. Survival rates for males were as follows: standard diet (38%, n = 21), standard diet plus colyte (83%, n = 42) and genistein diet (60%, n = 15). Survival rates for females were as follows: standard diet (47%, n = 19), standard diet plus colyte (71%, n = 38), and genistein diet (87%, n = 15). Average weight of male mice fed genistein diet increased by ~2.5 g more (p = 0.006) compared to those with colyte treatment. Genistein diet did not change final body weight of females. Expression of intestinal SGLT-1 increased 2-fold (p = 0.0005) with genistein diet in females (no change in males, p = 0.722). Expression of GLUT2 and GLUT5 was comparable between all diet groups. Genistein diet reduced the number of goblet cells per micrometer of crypt depth in female (p = 0.0483), yet was without effect in males (p = 0.7267). The results from this study demonstrate that supplementation of diet with genistein for ~45 days increases the survival rate of female ∆F508-CF mice (precluding the requirement for laxatives), and genistein only improves weight gain in males.
Collapse
Affiliation(s)
- Ryan Lord
- Department of Physiology, AZCOM, Midwestern University, 19555 N. 59th Avenue, Glendale, AZ 85308, USA.
| | - Nathan Fairbourn
- Department of Physiology, AZCOM, Midwestern University, 19555 N. 59th Avenue, Glendale, AZ 85308, USA.
| | - Charisma Mylavarapu
- Department of Physiology, AZCOM, Midwestern University, 19555 N. 59th Avenue, Glendale, AZ 85308, USA.
| | - Ammer Dbeis
- Department of Physiology, AZCOM, Midwestern University, 19555 N. 59th Avenue, Glendale, AZ 85308, USA.
| | - Taylor Bowman
- Department of Physiology, AZCOM, Midwestern University, 19555 N. 59th Avenue, Glendale, AZ 85308, USA.
| | - Archana Chandrashekar
- Department of Physiology, AZCOM, Midwestern University, 19555 N. 59th Avenue, Glendale, AZ 85308, USA.
| | - Tatum Banayat
- Department of Physiology, AZCOM, Midwestern University, 19555 N. 59th Avenue, Glendale, AZ 85308, USA.
| | - Craig A Hodges
- Department of Genetics & Genome Sciences & Department of Pediatrics, Case Western Reserve University, 10900 Euclid Avenue, 830 BRB, Cleveland, OH 44106, USA.
| | - Layla Al-Nakkash
- Department of Physiology, AZCOM, Midwestern University, 19555 N. 59th Avenue, Glendale, AZ 85308, USA.
| |
Collapse
|
13
|
Fukuda R, Okiyoneda T. Peripheral Protein Quality Control as a Novel Drug Target for CFTR Stabilizer. Front Pharmacol 2018; 9:1100. [PMID: 30319426 PMCID: PMC6170605 DOI: 10.3389/fphar.2018.01100] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 09/10/2018] [Indexed: 12/12/2022] Open
Abstract
Conformationally defective cystic fibrosis transmembrane conductance regulator (CFTR) including rescued ΔF508-CFTR is rapidly eliminated from the plasma membrane (PM) even in the presence of a CFTR corrector and potentiator, limiting the therapeutic effort of the combination therapy. CFTR elimination from the PM is determined by the conformation-dependent ubiquitination as a part of the peripheral quality control (PQC) mechanism. Recently, the molecular machineries responsible for the CFTR PQC mechanism which includes molecular chaperones and ubiquitination enzymes have been revealed. This review summarizes the molecular mechanism of the CFTR PQC and discusses the possibility that the peripheral ubiquitination mechanism becomes a novel drug target to develop the CFTR stabilizer as a novel class of CFTR modulator.
Collapse
Affiliation(s)
- Ryosuke Fukuda
- Department of Biomedical Chemistry, School of Science and Technology, Kwansei Gakuin University, Nishinomiya, Japan
| | - Tsukasa Okiyoneda
- Department of Biomedical Chemistry, School of Science and Technology, Kwansei Gakuin University, Nishinomiya, Japan
| |
Collapse
|
14
|
Liu J, Bihler H, Farinha CM, Awatade NT, Romão AM, Mercadante D, Cheng Y, Musisi I, Jantarajit W, Wang Y, Cai Z, Amaral MD, Mense M, Sheppard DN. Partial rescue of F508del-cystic fibrosis transmembrane conductance regulator channel gating with modest improvement of protein processing, but not stability, by a dual-acting small molecule. Br J Pharmacol 2018; 175:1017-1038. [PMID: 29318594 DOI: 10.1111/bph.14141] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 12/08/2017] [Accepted: 12/10/2017] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND AND PURPOSE Rescue of F508del-cystic fibrosis (CF) transmembrane conductance regulator (CFTR), the most common CF mutation, requires small molecules that overcome protein processing, stability and channel gating defects. Here, we investigate F508del-CFTR rescue by CFFT-004, a small molecule designed to independently correct protein processing and channel gating defects. EXPERIMENTAL APPROACH Using CFTR-expressing recombinant cells and CF patient-derived bronchial epithelial cells, we studied CFTR expression by Western blotting and channel gating and stability with the patch-clamp and Ussing chamber techniques. KEY RESULTS Chronic treatment with CFFT-004 improved modestly F508del-CFTR processing, but not its plasma membrane stability. By contrast, CFFT-004 rescued F508del-CFTR channel gating better than C18, an analogue of the clinically used CFTR corrector lumacaftor. Subsequent acute addition of CFFT-004, but not C18, potentiated F508del-CFTR channel gating. However, CFFT-004 was without effect on A561E-CFTR, a CF mutation with a comparable mechanism of CFTR dysfunction as F508del-CFTR. To investigate the mechanism of action of CFFT-004, we used F508del-CFTR revertant mutations. Potentiation by CFFT-004 was unaffected by revertant mutations, but correction was abolished by the revertant mutation G550E. These data suggest that correction, but not potentiation, by CFFT-004 might involve nucleotide-binding domain 1 of CFTR. CONCLUSIONS AND IMPLICATIONS CFFT-004 is a dual-acting small molecule with independent corrector and potentiator activities that partially rescues F508del-CFTR in recombinant cells and native airway epithelia. The limited efficacy and potency of CFFT-004 suggests that combinations of small molecules targeting different defects in F508del-CFTR might be a more effective therapeutic strategy than a single agent.
Collapse
Affiliation(s)
- Jia Liu
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Hermann Bihler
- Cystic Fibrosis Foundation Therapeutics, Lexington, MA, USA
| | - Carlos M Farinha
- Faculty of Sciences, BioISI - Biosystems and Integrative Sciences Institute, University of Lisboa, Lisboa, Portugal
| | - Nikhil T Awatade
- Faculty of Sciences, BioISI - Biosystems and Integrative Sciences Institute, University of Lisboa, Lisboa, Portugal
| | - Ana M Romão
- Faculty of Sciences, BioISI - Biosystems and Integrative Sciences Institute, University of Lisboa, Lisboa, Portugal
| | | | - Yi Cheng
- Cystic Fibrosis Foundation Therapeutics, Lexington, MA, USA
| | - Isaac Musisi
- Cystic Fibrosis Foundation Therapeutics, Lexington, MA, USA
| | - Walailak Jantarajit
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.,Center of Calcium and Bone Research and Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Yiting Wang
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Zhiwei Cai
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Margarida D Amaral
- Faculty of Sciences, BioISI - Biosystems and Integrative Sciences Institute, University of Lisboa, Lisboa, Portugal
| | - Martin Mense
- Cystic Fibrosis Foundation Therapeutics, Lexington, MA, USA
| | - David N Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| |
Collapse
|
15
|
Abstract
Nucleic acid therapeutics are an established class of drugs that enable specific targeting of a gene of interest. This diverse family of drugs includes antisense oligonucleotides, siRNAs, and mRNA replacement therapies, which can elicit both gene repression and activation, primarily at the RNA level. Recent advances in medicinal chemistry have increased drug potency and enhanced delivery and distribution to a broad array of tissue and cell types. A key advantage of nucleic acid therapeutics is in their application to monogenic diseases. Cystic fibrosis (CF) is one such disease that affects ∼70,000 people globally. This severe disease is an excellent candidate for nucleic acid therapies, as it is due to a genetic defect in a single epithelial chloride channel. Although CF affects many tissues, the primary cause of patient mortality is lung disease. Here we review the various nucleic acid therapeutic modalities and their mechanisms of action, the opportunities and challenges associated with application of nucleic acid drugs to the lung pathology of CF, and the current state and prospects for nucleic acid drugs for the treatment of CF.
Collapse
Affiliation(s)
| | - Shuling Guo
- Ionis Pharmaceuticals, Inc. , Carlsbad, California
| |
Collapse
|
16
|
Chaperones rescue the energetic landscape of mutant CFTR at single molecule and in cell. Nat Commun 2017; 8:398. [PMID: 28855508 PMCID: PMC5577305 DOI: 10.1038/s41467-017-00444-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 06/29/2017] [Indexed: 12/14/2022] Open
Abstract
Molecular chaperones are pivotal in folding and degradation of the cellular proteome but their impact on the conformational dynamics of near-native membrane proteins with disease relevance remains unknown. Here we report the effect of chaperone activity on the functional conformation of the temperature-sensitive mutant cystic fibrosis channel (∆F508-CFTR) at the plasma membrane and after reconstitution into phospholipid bilayer. Thermally induced unfolding at 37 °C and concomitant functional inactivation of ∆F508-CFTR are partially suppressed by constitutive activity of Hsc70 and Hsp90 chaperone/co-chaperone at the plasma membrane and post-endoplasmic reticulum compartments in vivo, and at single-molecule level in vitro, indicated by kinetic and thermodynamic remodeling of the mutant gating energetics toward its wild-type counterpart. Thus, molecular chaperones can contribute to functional maintenance of ∆F508-CFTR by reshaping the conformational energetics of its final fold, a mechanism with implication in the regulation of metastable ABC transporters and other plasma membrane proteins activity in health and diseases. The F508 deletion (F508del) in the cystic fibrosis transmembrane conductance regulator (CFTR) is the most common CF causing mutation. Here the authors show that cytosolic chaperones shift the F508del channel conformation to the native fold by kinetic and thermodynamic remodelling of the gating energetics towards that of wild-type CTFR.
Collapse
|
17
|
Billet A, Froux L, Hanrahan JW, Becq F. Development of Automated Patch Clamp Technique to Investigate CFTR Chloride Channel Function. Front Pharmacol 2017; 8:195. [PMID: 28439239 PMCID: PMC5383655 DOI: 10.3389/fphar.2017.00195] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 03/24/2017] [Indexed: 11/13/2022] Open
Abstract
The chloride (Cl-) channel cystic fibrosis transmembrane conductance regulator (CFTR) is defective in cystic fibrosis (CF), and mutation of its encoding gene leads to various defects such as retention of the misfolded protein in the endoplasmic reticulum, reduced stability at the plasma membrane, abnormal channel gating with low open probability, and thermal instability, which leads to inactivation of the channel at physiological temperature. Pharmacotherapy is one major therapeutic approach in the CF field and needs sensible and fast tools to identify promising compounds. The high throughput screening assays available are often fast and sensible techniques but with lack of specificity. Few works used automated patch clamp (APC) for CFTR recording, and none have compared conventional and planar techniques and demonstrated their capabilities for different types of experiments. In this study, we evaluated the use of planar parallel APC technique for pharmacological search of CFTR-trafficking correctors and CFTR function modulators. Using optimized conditions, we recorded both wt- and corrected F508del-CFTR Cl- currents with automated whole-cell patch clamp and compared the data to results obtained with conventional manual whole-cell patch clamp. We found no significant difference in patch clamp parameters such as cell capacitance and series resistance between automated and manual patch clamp. Also, the results showed good similarities of CFTR currents recording between the two methods. We showed that similar stimulation protocols could be used in both manual and automatic techniques allowing precise control of temperature, classic I/V relationship, and monitoring of current stability in time. In conclusion, parallel patch-clamp recording allows rapid and efficient investigation of CFTR currents with a variety of tests available and could be considered as new tool for medium throughput screening in CF pharmacotherapy.
Collapse
Affiliation(s)
- Arnaud Billet
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers - ERL7368, Centre National de la Recherche ScientifiquePoitiers, France
| | - Lionel Froux
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers - ERL7368, Centre National de la Recherche ScientifiquePoitiers, France
| | - John W Hanrahan
- Department of Physiology, McGill University, MontrealQC, Canada.,McGill Cystic Fibrosis Translational Research Centre, MontrealQC, Canada.,The Research Institute of the McGill University Health Centre, MontrealQC, Canada
| | - Frederic Becq
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers - ERL7368, Centre National de la Recherche ScientifiquePoitiers, France
| |
Collapse
|
18
|
Meng X, Wang Y, Wang X, Wrennall JA, Rimington TL, Li H, Cai Z, Ford RC, Sheppard DN. Two Small Molecules Restore Stability to a Subpopulation of the Cystic Fibrosis Transmembrane Conductance Regulator with the Predominant Disease-causing Mutation. J Biol Chem 2017; 292:3706-3719. [PMID: 28087700 PMCID: PMC5339754 DOI: 10.1074/jbc.m116.751537] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 01/12/2017] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is caused by mutations that disrupt the plasma membrane expression, stability, and function of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel. Two small molecules, the CFTR corrector lumacaftor and the potentiator ivacaftor, are now used clinically to treat CF, although some studies suggest that they have counteracting effects on CFTR stability. Here, we investigated the impact of these compounds on the instability of F508del-CFTR, the most common CF mutation. To study individual CFTR Cl- channels, we performed single-channel recording, whereas to assess entire CFTR populations, we used purified CFTR proteins and macroscopic CFTR Cl- currents. At 37 °C, low temperature-rescued F508del-CFTR more rapidly lost function in cell-free membrane patches and showed altered channel gating and current flow through open channels. Compared with purified wild-type CFTR, the full-length F508del-CFTR was about 10 °C less thermostable. Lumacaftor partially stabilized purified full-length F508del-CFTR and slightly delayed deactivation of individual F508del-CFTR Cl- channels. By contrast, ivacaftor further destabilized full-length F508del-CFTR and accelerated channel deactivation. Chronic (prolonged) co-incubation of F508del-CFTR-expressing cells with lumacaftor and ivacaftor deactivated macroscopic F508del-CFTR Cl- currents. However, at the single-channel level, chronic co-incubation greatly increased F508del-CFTR channel activity and temporal stability in most, but not all, cell-free membrane patches. We conclude that chronic lumacaftor and ivacaftor co-treatment restores stability in a small subpopulation of F508del-CFTR Cl- channels but that the majority remain destabilized. A fuller understanding of these effects and the characterization of the small F508del-CFTR subpopulation might be crucial for CF therapy development.
Collapse
Affiliation(s)
- Xin Meng
- From the Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PL, United Kingdom and
| | - Yiting Wang
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Xiaomeng Wang
- From the Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PL, United Kingdom and
| | - Joe A Wrennall
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Tracy L Rimington
- From the Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PL, United Kingdom and
| | - Hongyu Li
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Zhiwei Cai
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Robert C Ford
- From the Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PL, United Kingdom and
| | - David N Sheppard
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| |
Collapse
|
19
|
Veit G, Avramescu RG, Chiang AN, Houck SA, Cai Z, Peters KW, Hong JS, Pollard HB, Guggino WB, Balch WE, Skach WR, Cutting GR, Frizzell RA, Sheppard DN, Cyr DM, Sorscher EJ, Brodsky JL, Lukacs GL. From CFTR biology toward combinatorial pharmacotherapy: expanded classification of cystic fibrosis mutations. Mol Biol Cell 2016; 27:424-33. [PMID: 26823392 PMCID: PMC4751594 DOI: 10.1091/mbc.e14-04-0935] [Citation(s) in RCA: 369] [Impact Index Per Article: 46.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
More than 2000 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) have been described that confer a range of molecular cell biological and functional phenotypes. Most of these mutations lead to compromised anion conductance at the apical plasma membrane of secretory epithelia and cause cystic fibrosis (CF) with variable disease severity. Based on the molecular phenotypic complexity of CFTR mutants and their susceptibility to pharmacotherapy, it has been recognized that mutations may impose combinatorial defects in CFTR channel biology. This notion led to the conclusion that the combination of pharmacotherapies addressing single defects (e.g., transcription, translation, folding, and/or gating) may show improved clinical benefit over available low-efficacy monotherapies. Indeed, recent phase 3 clinical trials combining ivacaftor (a gating potentiator) and lumacaftor (a folding corrector) have proven efficacious in CF patients harboring the most common mutation (deletion of residue F508, ΔF508, or Phe508del). This drug combination was recently approved by the U.S. Food and Drug Administration for patients homozygous for ΔF508. Emerging studies of the structural, cell biological, and functional defects caused by rare mutations provide a new framework that reveals a mixture of deficiencies in different CFTR alleles. Establishment of a set of combinatorial categories of the previously defined basic defects in CF alleles will aid the design of even more efficacious therapeutic interventions for CF patients.
Collapse
Affiliation(s)
- Gudio Veit
- Department of Physiology, McGill University, Montréal, QC H3G 1Y6, Canada
| | - Radu G Avramescu
- Department of Physiology, McGill University, Montréal, QC H3G 1Y6, Canada
| | - Annette N Chiang
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260
| | - Scott A Houck
- Marsico Lung Institute, School of Medicine, University of North Carolina, Chapel Hill, NC 27514
| | - Zhiwei Cai
- School of Physiology & Pharmacology, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Kathryn W Peters
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261
| | - Jeong S Hong
- Department of Cellular, Developmental, and Integrative Biology, University of Alabama, Birmingham, AL 35294
| | - Harvey B Pollard
- Department of Anatomy, Physiology and Genetics and Center for Medical Proteomics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814
| | - William B Guggino
- Department of Physiology, Johns Hopkins University, Baltimore, MD 21205
| | - William E Balch
- Department of Chemical Physiology, Skaggs Institute of Chemical Physiology, Scripps Research Institute, La Jolla, CA 92037
| | - William R Skach
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, OR 97239
| | - Garry R Cutting
- McKusick-Nathans Institute of Genetic Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD 21205
| | - Raymond A Frizzell
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261
| | - David N Sheppard
- School of Physiology & Pharmacology, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Douglas M Cyr
- Marsico Lung Institute, School of Medicine, University of North Carolina, Chapel Hill, NC 27514
| | - Eric J Sorscher
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260
| | - Gergely L Lukacs
- Department of Physiology, McGill University, Montréal, QC H3G 1Y6, Canada Department of Biochemistry, McGill University, Montréal, QC H3G 1Y6, Canada GRASP, McGill University, Montréal, QC H3G 1Y6, Canada
| |
Collapse
|
20
|
Cai Z, Palmai-Pallag T, Khuituan P, Mutolo MJ, Boinot C, Liu B, Scott-Ward TS, Callebaut I, Harris A, Sheppard DN. Impact of the F508del mutation on ovine CFTR, a Cl- channel with enhanced conductance and ATP-dependent gating. J Physiol 2015; 593:2427-46. [PMID: 25763566 DOI: 10.1113/jp270227] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/02/2015] [Indexed: 12/20/2022] Open
Abstract
KEY POINTS Malfunction of the cystic fibrosis transmembrane conductance regulator (CFTR), a gated pathway for chloride movement, causes the common life-shortening genetic disease cystic fibrosis (CF). Towards the development of a sheep model of CF, we have investigated the function of sheep CFTR. We found that sheep CFTR was noticeably more active than human CFTR, while the most common CF mutation, F508del, had reduced impact on sheep CFTR function. Our results demonstrate that subtle changes in protein structure have marked effects on CFTR function and the consequences of the CF mutation F508del. ABSTRACT Cross-species comparative studies are a powerful approach to understanding the epithelial Cl(-) channel cystic fibrosis transmembrane conductance regulator (CFTR), which is defective in the genetic disease cystic fibrosis (CF). Here, we investigate the single-channel behaviour of ovine CFTR and the impact of the most common CF mutation, F508del-CFTR, using excised inside-out membrane patches from transiently transfected CHO cells. Like human CFTR, ovine CFTR formed a weakly inwardly rectifying Cl(-) channel regulated by PKA-dependent phosphorylation, inhibited by the open-channel blocker glibenclamide. However, for three reasons, ovine CFTR was noticeably more active than human CFTR. First, single-channel conductance was increased. Second, open probability was augmented because the frequency and duration of channel openings were increased. Third, with enhanced affinity and efficacy, ATP more strongly stimulated ovine CFTR channel gating. Consistent with these data, the CFTR modulator phloxine B failed to potentiate ovine CFTR Cl(-) currents. Similar to its impact on human CFTR, the F508del mutation caused a temperature-sensitive folding defect, which disrupted ovine CFTR protein processing and reduced membrane stability. However, the F508del mutation had reduced impact on ovine CFTR channel gating in contrast to its marked effects on human CFTR. We conclude that ovine CFTR forms a regulated Cl(-) channel with enhanced conductance and ATP-dependent channel gating. This phylogenetic analysis of CFTR structure and function demonstrates that subtle changes in structure have pronounced effects on channel function and the consequences of the CF mutation F508del.
Collapse
Affiliation(s)
- Zhiwei Cai
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Timea Palmai-Pallag
- Human Molecular Genetics Program, Lurie Children's Research Center and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, 60614, USA.,Harris Laboratory, formerly at the Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Pissared Khuituan
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol, BS8 1TD, UK.,Center of Calcium and Bone Research, Department of Physiology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Michael J Mutolo
- Human Molecular Genetics Program, Lurie Children's Research Center and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, 60614, USA
| | - Clément Boinot
- Institut de Physiologie et Biologie Cellulaires, Université de Poitiers, CNRS FRE 3511, 86022, Poitiers, France
| | - Beihui Liu
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Toby S Scott-Ward
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Isabelle Callebaut
- IMPMC, Sorbonne Universités - UPMC Univ Paris 06, UMR CNRS 7590, Museum National d'Histoire Naturelle, IRD UMR 206, IUC, 75005, Paris, France
| | - Ann Harris
- Human Molecular Genetics Program, Lurie Children's Research Center and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, 60614, USA
| | - David N Sheppard
- School of Physiology and Pharmacology, University of Bristol, Medical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| |
Collapse
|
21
|
Awatade NT, Uliyakina I, Farinha CM, Clarke LA, Mendes K, Solé A, Pastor J, Ramos MM, Amaral MD. Measurements of Functional Responses in Human Primary Lung Cells as a Basis for Personalized Therapy for Cystic Fibrosis. EBioMedicine 2014; 2:147-53. [PMID: 26137539 PMCID: PMC4484512 DOI: 10.1016/j.ebiom.2014.12.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/16/2014] [Accepted: 12/16/2014] [Indexed: 01/08/2023] Open
Abstract
Background The best investigational drug to treat cystic fibrosis (CF) patients with the most common CF-causing mutation (F508del) is VX-809 (lumacaftor) which recently succeeded in Phase III clinical trial in combination with ivacaftor. This corrector rescues F508del-CFTR from its abnormal intracellular localization to the cell surface, a traffic defect shared by all Class II CFTR mutants. Our goal here is to test the efficacy of lumacaftor in other Class II mutants in primary human bronchial epithelial (HBE) cells derived from CF patients. Methods The effect of lumacaftor was investigated in primary HBE cells from non-CF and CF patients with F508del/F508del, A561E/A561E, N1303K/G542X, F508del/G542X and F508del/Y1092X genotypes by measurements of Forskolin plus Genistein-inducible equivalent short-circuit current (Ieq-SC-Fsk + Gen) in perfused open-circuit Ussing chambers. Efficacy of corrector C18 was also assessed on A561E/A561E and F508del/F508del cells. Results Our data indicate that A561E (when present in both alleles) responds positively to lumacaftor treatment at equivalent efficacy of F508del in primary HBE cells. Similarly, lumacaftor has a positive impact on Y1092X, but not on N1303K. Our data also show that cells with only one copy of F508del-CFTR respond less to VX-809. Moreover, there is great variability in lumacaftor responses among F508del-homozygous cells from different donors. Compound C18 failed to rescue A561E-CFTR but not in F508del-CFTR, thus plausibly it has a different mechanism of action distinct from lumacaftor. Conclusions CF patients with A561E (and likely also those with Y1029X) can potentially benefit from lumacaftor. Moreover, the methodology used here exemplifies how ex vivo approaches may apply personalized therapies to CF and possibly other respiratory diseases. A561E and Y1092X CFTR mutations (but not N1303K) respond positively to lumacaftor treatment. One copy of F508del-CFTR responds less to lumacaftor than 2 copies and F508del-responses vary greatly. CF patients with A561E (and likely also those with Y1029X) can potentially benefit from lumacaftor. The methodology used here exemplifies how ex vivo approaches may apply personalized therapies to CF and possibly other respiratory diseases.
Collapse
Key Words
- (ΔIeq-sc), equivalent short-circuit currents
- CF, cystic fibrosis
- CFTR, cystic fibrosis transmembrane conductance regulator
- ENaC, epithelial Na+ channel
- Fsk, forskolin
- Gen, Genistein
- HBE (cells), human bronchial epithelial cells
- Innovative treatments
- Mutation-specific therapies
- Personalized medicine
- Rare diseases
- Rte, transepithelial resistance.
- SEM, standard error of the mean
- TEER, transepithelial electrical resistance
- Vte, transepithelial voltage
Collapse
Affiliation(s)
- Nikhil T Awatade
- University of Lisboa, Faculty of Sciences, BioFIG-Center for Biodiversity, Functional and Integrative Genomics, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - Inna Uliyakina
- University of Lisboa, Faculty of Sciences, BioFIG-Center for Biodiversity, Functional and Integrative Genomics, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - Carlos M Farinha
- University of Lisboa, Faculty of Sciences, BioFIG-Center for Biodiversity, Functional and Integrative Genomics, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - Luka A Clarke
- University of Lisboa, Faculty of Sciences, BioFIG-Center for Biodiversity, Functional and Integrative Genomics, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - Karina Mendes
- University of Lisboa, Faculty of Sciences, BioFIG-Center for Biodiversity, Functional and Integrative Genomics, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - Amparo Solé
- Adult Cystic Fibrosis Unit, University Hospital la Fe, Boulevar Sur, 46026 Valencia, Spain
| | - Juan Pastor
- Thoracic Surgery Service, University Hospital la Fe, Av. Campanar 21, 46009 Valencia, Spain
| | - Maria Margarida Ramos
- University of Lisboa, Faculty of Sciences, BioFIG-Center for Biodiversity, Functional and Integrative Genomics, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - Margarida D Amaral
- University of Lisboa, Faculty of Sciences, BioFIG-Center for Biodiversity, Functional and Integrative Genomics, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| |
Collapse
|
22
|
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.
Collapse
Affiliation(s)
- Xuehong Liu
- Department of Physiology & Pharmacology, Oregon Health & Science University , Portland, Oregon 97239, United States
| | | |
Collapse
|