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Chen J, Thrasher K, Fu L, Wang W, Aghamohammadzadeh S, Wen H, Tang L, Keeling KM, Falk Libby E, Bedwell DM, Rowe SM. The synthetic aminoglycoside ELX-02 induces readthrough of G550X-CFTR producing superfunctional protein that can be further enhanced by CFTR modulators. Am J Physiol Lung Cell Mol Physiol 2023; 324:L756-L770. [PMID: 37014818 PMCID: PMC10202470 DOI: 10.1152/ajplung.00038.2023] [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] [Received: 01/30/2023] [Revised: 03/29/2023] [Accepted: 04/02/2023] [Indexed: 04/05/2023] Open
Abstract
Ten percent of cystic fibrosis (CF) patients carry a premature termination codon (PTC); no mutation-specific therapies exist for these individuals. ELX-02, a synthetic aminoglycoside, suppresses translation termination at PTCs (i.e., readthrough) by promoting the insertion of an amino acid at the PTC and restoring expression of full-length CFTR protein. The identity of amino acids inserted at PTCs affects the processing and function of the resulting full-length CFTR protein. We examined readthrough of the rare G550X-CFTR nonsense mutation due to its unique properties. We found that forskolin-induced swelling in G550X patient-derived intestinal organoids (PDOs) was significantly higher than in G542X PDOs (both UGA PTCs) with ELX-02 treatment, indicating greater CFTR function from the G550X allele. Using mass spectrometry, we identified tryptophan as the sole amino acid inserted in the G550X position during ELX-02- or G418-mediated readthrough, which differs from the three amino acids (cysteine, arginine, and tryptophan) inserted in the G542X position after treatment with G418. Compared with wild-type CFTR, Fischer rat thyroid (FRT) cells expressing the G550W-CFTR variant protein exhibited significantly increased forskolin-activated Cl- conductance, and G550W-CFTR channels showed increased PKA sensitivity and open probability. After treatment with ELX-02 and CFTR correctors, CFTR function rescued from the G550X allele in FRTs reached 20-40% of the wild-type level. These results suggest that readthrough of G550X produces greater CFTR function because of gain-of-function properties of the CFTR readthrough product that stem from its location in the signature LSGGQ motif found in ATP-binding cassette (ABC) transporters. G550X may be a particularly sensitive target for translational readthrough therapy.NEW & NOTEWORTHY We found that forskolin-induced swelling in G550X-CFTR patient-derived intestinal organoids (PDOs) was significantly higher than in G542X-CFTR PDOs after treatment with ELX-02. Tryptophan (W) was the sole amino acid inserted in the G550X position after readthrough. Resulting G550W-CFTR protein exhibited supernormal CFTR activity, PKA sensitivity, and open probability. These results show that aminoglycoside-induced readthrough of G550X produces greater CFTR function because of the gain-of-function properties of the CFTR readthrough product.
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Affiliation(s)
- Jianguo Chen
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Kari Thrasher
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Lianwu Fu
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Wei Wang
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | | | - Hui Wen
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Liping Tang
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Kim M Keeling
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Emily Falk Libby
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - David M Bedwell
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Steven M Rowe
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
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2
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Rzeznitzeck J, Breves G, Rychlik I, Hoerr FJ, von Altrock A, Rath A, Rautenschlein S. The effect of Campylobacter jejuni and Campylobacter coli colonization on the gut morphology, functional integrity, and microbiota composition of female turkeys. Gut Pathog 2022; 14:33. [PMID: 35922874 PMCID: PMC9347085 DOI: 10.1186/s13099-022-00508-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/21/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Campylobacter (C.) species are the most common bacterial cause of foodborne diarrhea in humans. Despite colonization, most animals do not show clinical signs, making recognition of affected flocks and disruption of the infection chain before slaughter challenging. Turkeys are often cocolonized with C. jejuni and C. coli. To understand the pathogen-host-interaction in the context of two different Campylobacter species, we compared the colonization patterns and quantities in mono- and co-colonized female commercial turkeys. In three repeated experiments we investigated the impact on gut morphology, functional integrity, and microbiota composition as parameters of gut health at seven, 14, and 28 days post-inoculation. RESULTS Despite successful Campylobacter colonization, clinical signs or pathological lesions were not observed. C. coli persistently colonized the distal intestinal tract and at a higher load compared to C. jejuni. Both strains were isolated from livers and spleens, occurring more frequently in C. jejuni- and co-inoculated turkeys. Especially in C. jejuni-positive animals, translocation was accompanied by local heterophil infiltration, villus blunting, and shallower crypts. Increased permeability and lower electrogenic ion transport of the cecal mucosa were also observed. A lower relative abundance of Clostridia UCG-014, Lachnospiraceae, and Lactobacillaceae was noted in all inoculated groups compared to controls. CONCLUSIONS In sum, C. jejuni affects gut health and may interfere with productivity in turkeys. Despite a higher cecal load, the impact of C. coli on investigated parameters was less pronounced. Interestingly, gut morphology and functional integrity were also less affected in co-inoculated animals while the C. jejuni load decreased over time, suggesting C. coli may outcompete C. jejuni. Since a microbiota shift was observed in all inoculated groups, future Campylobacter intervention strategies may involve stabilization of the gut microbiota, making it more resilient to Campylobacter colonization in the first place.
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Affiliation(s)
- Janina Rzeznitzeck
- Clinic for Poultry, University of Veterinary Medicine Hannover, Foundation, Buenteweg 17, 30559, Hannover, Germany
| | - Gerhard Breves
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany
| | - Ivan Rychlik
- Veterinary Research Institute, Hudcova 296/70, 621 00, Brno, Czech Republic
| | - Frederic J Hoerr
- Veterinary Diagnostics Pathology, LLC, 638 South Fort Valley Road, VA, 22652, Fort Valley, United States of America
| | - Alexandra von Altrock
- Clinic for Swine, Small Ruminants and Forensic Medicine, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany
| | - Alexandra Rath
- Clinic for Swine, Small Ruminants and Forensic Medicine, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany
| | - Silke Rautenschlein
- Clinic for Poultry, University of Veterinary Medicine Hannover, Foundation, Buenteweg 17, 30559, Hannover, Germany.
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3
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Assays of CFTR Function In Vitro, Ex Vivo and In Vivo. Int J Mol Sci 2022; 23:ijms23031437. [PMID: 35163362 PMCID: PMC8836180 DOI: 10.3390/ijms23031437] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/12/2022] [Accepted: 01/21/2022] [Indexed: 12/22/2022] Open
Abstract
Cystic fibrosis, a multi-organ genetic disease, is characterized by abnormal function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride channel at the apical membrane of several epithelia. In recent years, therapeutic strategies have been developed to correct the CFTR defect. To evaluate CFTR function at baseline for diagnosis, or the efficacy of CFTR-restoring therapy, reliable tests are needed to measure CFTR function, in vitro, ex vivo and in vivo. In vitro techniques either directly or indirectly measure ion fluxes; direct measurement of ion fluxes and quenching of fluorescence in cell-based assays, change in transmembrane voltage or current in patch clamp or Ussing chamber, swelling of CFTR-containing organoids by secondary water influx upon CFTR activation. Several cell or tissue types can be used. Ex vivo and in vivo assays similarly evaluate current (intestinal current measurement) and membrane potential differences (nasal potential difference), on tissues from individual patients. In the sweat test, the most frequently used in vivo evaluation of CFTR function, chloride concentration or stimulated sweat rate can be directly measured. Here, we will describe the currently available bio-assays for quantitative evaluation of CFTR function, their indications, advantages and disadvantages, and correlation with clinical outcome measures.
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4
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Salto R, Giron MD, Puente-Muñoz V, Vilchez JD, Espinar-Barranco L, Valverde-Pozo J, Arosio D, Paredes JM. New Red-Emitting Chloride-Sensitive Fluorescent Protein with Biological Uses. ACS Sens 2021; 6:2563-2573. [PMID: 34148347 PMCID: PMC8478333 DOI: 10.1021/acssensors.1c00094] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/11/2021] [Indexed: 02/06/2023]
Abstract
A new chloride-sensitive red fluorescent protein derived from Entacmaea quadricolor is described. We found that mBeRFP exhibited moderate sensitivity to chloride and, via site-directed mutagenesis (S94V and R205Y), we increased the chloride affinity by more than an order of magnitude (kd = 106 ± 6 mM) at physiological pH. In addition, cis-trans isomerization of the chromophore produces a dual emission band with different chloride sensitivities, which allowed us to develop a ratiometric methodology to measure intracellular chloride concentrations.
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Affiliation(s)
- Rafael Salto
- Department
of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Unidad
de Excelencia en Quimica Aplicada a Biomedicina y Medioambiente (UEQ), University of Granada, Cartuja Campus, 18071 Granada, Spain
| | - Maria D. Giron
- Department
of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Unidad
de Excelencia en Quimica Aplicada a Biomedicina y Medioambiente (UEQ), University of Granada, Cartuja Campus, 18071 Granada, Spain
| | - Virginia Puente-Muñoz
- Department
of Physical Chemistry, Faculty of Pharmacy, Unidad de Excelencia en
Quimica Aplicada a Biomedicina y Medioambiente (UEQ), University of Granada, C. U. Cartuja, 18071 Granada, Spain
| | - Jose D. Vilchez
- Department
of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Unidad
de Excelencia en Quimica Aplicada a Biomedicina y Medioambiente (UEQ), University of Granada, Cartuja Campus, 18071 Granada, Spain
| | - Laura Espinar-Barranco
- Department
of Physical Chemistry, Faculty of Pharmacy, Unidad de Excelencia en
Quimica Aplicada a Biomedicina y Medioambiente (UEQ), University of Granada, C. U. Cartuja, 18071 Granada, Spain
| | - Javier Valverde-Pozo
- Department
of Physical Chemistry, Faculty of Pharmacy, Unidad de Excelencia en
Quimica Aplicada a Biomedicina y Medioambiente (UEQ), University of Granada, C. U. Cartuja, 18071 Granada, Spain
| | - Daniele Arosio
- Consiglio
Nazionale delle Ricerche (CNR), Istituto di Biofisica (IBF-CNR), 38123 Trento, Italy
| | - Jose M. Paredes
- Department
of Physical Chemistry, Faculty of Pharmacy, Unidad de Excelencia en
Quimica Aplicada a Biomedicina y Medioambiente (UEQ), University of Granada, C. U. Cartuja, 18071 Granada, Spain
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5
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Grand DL, Gosling M, Baettig U, Bahra P, Bala K, Brocklehurst C, Budd E, Butler R, Cheung AK, Choudhury H, Collingwood SP, Cox B, Danahay H, Edwards L, Everatt B, Glaenzel U, Glotin AL, Groot-Kormelink P, Hall E, Hatto J, Howsham C, Hughes G, King A, Koehler J, Kulkarni S, Lightfoot M, Nicholls I, Page C, Pergl-Wilson G, Popa MO, Robinson R, Rowlands D, Sharp T, Spendiff M, Stanley E, Steward O, Taylor RJ, Tranter P, Wagner T, Watson H, Williams G, Wright P, Young A, Sandham DA. Discovery of Icenticaftor (QBW251), a Cystic Fibrosis Transmembrane Conductance Regulator Potentiator with Clinical Efficacy in Cystic Fibrosis and Chronic Obstructive Pulmonary Disease. J Med Chem 2021; 64:7241-7260. [PMID: 34028270 DOI: 10.1021/acs.jmedchem.1c00343] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) ion channel are established as the primary causative factor in the devastating lung disease cystic fibrosis (CF). More recently, cigarette smoke exposure has been shown to be associated with dysfunctional airway epithelial ion transport, suggesting a role for CFTR in the pathogenesis of chronic obstructive pulmonary disease (COPD). Here, the identification and characterization of a high throughput screening hit 6 as a potentiator of mutant human F508del and wild-type CFTR channels is reported. The design, synthesis, and biological evaluation of compounds 7-33 to establish structure-activity relationships of the scaffold are described, leading to the identification of clinical development compound icenticaftor (QBW251) 33, which has subsequently progressed to deliver two positive clinical proofs of concept in patients with CF and COPD and is now being further developed as a novel therapeutic approach for COPD patients.
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Affiliation(s)
- Darren Le Grand
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Martin Gosling
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Urs Baettig
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Parmjit Bahra
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Kamlesh Bala
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Cara Brocklehurst
- Novartis Institutes for Biomedical Research, Novartis Campus, Basel, CH 4002, Switzerland
| | - Emma Budd
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Rebecca Butler
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Atwood K Cheung
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Hedaythul Choudhury
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Stephen P Collingwood
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Brian Cox
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Henry Danahay
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Lee Edwards
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Brian Everatt
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Ulrike Glaenzel
- Novartis Institutes for Biomedical Research, Novartis Campus, Basel, CH 4002, Switzerland
| | - Anne-Lise Glotin
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Paul Groot-Kormelink
- Novartis Institutes for Biomedical Research, Novartis Campus, Basel, CH 4002, Switzerland
| | - Edward Hall
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Julia Hatto
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Catherine Howsham
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Glyn Hughes
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Anna King
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Julia Koehler
- Novartis Institutes for Biomedical Research, Novartis Campus, Basel, CH 4002, Switzerland
| | - Swarupa Kulkarni
- Novartis Institutes for Biomedical Research, East Hanover, New Jersey 07936, United States
| | - Megan Lightfoot
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Ian Nicholls
- Novartis Institutes for Biomedical Research, Novartis Campus, Basel, CH 4002, Switzerland
| | - Christopher Page
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Giles Pergl-Wilson
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Mariana Oana Popa
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Richard Robinson
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - David Rowlands
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Tom Sharp
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Matthew Spendiff
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Emily Stanley
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Oliver Steward
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Roger J Taylor
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Pamela Tranter
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Trixie Wagner
- Novartis Institutes for Biomedical Research, Novartis Campus, Basel, CH 4002, Switzerland
| | - Hazel Watson
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Gareth Williams
- Novartis Institutes for Biomedical Research, Novartis Campus, Basel, CH 4002, Switzerland
| | - Penny Wright
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - Alice Young
- Novartis Institutes for Biomedical Research, Horsham Research Center, Wimblehurst Road, Horsham RH12 5AB, U.K
| | - David A Sandham
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139, United States
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6
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Heterogeneous expression of CFTR in insulin-secreting β-cells of the normal human islet. PLoS One 2020; 15:e0242749. [PMID: 33264332 PMCID: PMC7710116 DOI: 10.1371/journal.pone.0242749] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 11/06/2020] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is due to mutations in the CF-transmembrane conductance regulator (CFTR) and CF-related diabetes (CFRD) is its most common co-morbidity, affecting ~50% of all CF patients, significantly influencing pulmonary function and longevity. Yet, the complex pathogenesis of CFRD remains unclear. Two non-mutually exclusive underlying mechanisms have been proposed in CFRD: i) damage of the endocrine cells secondary to the severe exocrine pancreatic pathology and ii) intrinsic β-cell impairment of the secretory response in combination with other factors. The later has proven difficult to determine due to low expression of CFTR in β-cells, which results in the general perception that this Cl−channel does not participate in the modulation of insulin secretion or the development of CFRD. The objective of the present work is to demonstrate CFTR expression at the molecular and functional levels in insulin-secreting β-cells in normal human islets, where it seems to play a role. Towards this end, we have used immunofluorescence confocal and immunofluorescence microscopy, immunohistochemistry, RT-qPCR, Western blotting, pharmacology, electrophysiology and insulin secretory studies in normal human, rat and mouse islets. Our results demonstrate heterogeneous CFTR expression in human, mouse and rat β-cells and provide evidence that pharmacological inhibition of CFTR influences basal and stimulated insulin secretion in normal mouse islets but not in islets lacking this channel, despite being detected by electrophysiological means in ~30% of β-cells. Therefore, our results demonstrate a potential role for CFTR in the pancreatic β-cell secretory response suggesting that intrinsic β-cell dysfunction may also participate in the pathogenesis of CFRD.
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7
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Cell-Based Therapeutic Approaches for Cystic Fibrosis. Int J Mol Sci 2020; 21:ijms21155219. [PMID: 32718005 PMCID: PMC7432606 DOI: 10.3390/ijms21155219] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 01/01/2023] Open
Abstract
Cystic Fibrosis (CF) is a chronic autosomal recessive disease caused by defects in the cystic fibrosis transmembrane conductance regulator gene (CFTR). Cystic Fibrosis affects multiple organs but progressive remodeling of the airways, mucus accumulation, and chronic inflammation in the lung, result in lung disease as the major cause of morbidity and mortality. While advances in management of CF symptoms have increased the life expectancy of this devastating disease, and there is tremendous excitement about the potential of new agents targeting the CFTR molecule itself, there is still no curative treatment. With the recent advances in the identification of endogenous airway progenitor cells and in directed differentiation of pluripotent cell sources, cell-based therapeutic approaches for CF have become a plausible treatment method with the potential to ultimately cure the disease. In this review, we highlight the current state of cell therapy in the CF field focusing on the relevant autologous and allogeneic cell populations under investigation and the challenges associated with their use. In addition, we present advances in induced pluripotent stem (iPS) cell approaches and emerging new genetic engineering methods, which have the capacity to overcome the current limitations hindering cell therapy approaches.
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8
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Correctors modify the bicarbonate permeability of F508del-CFTR. Sci Rep 2020; 10:8440. [PMID: 32439937 PMCID: PMC7242338 DOI: 10.1038/s41598-020-65287-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/29/2020] [Indexed: 01/17/2023] Open
Abstract
One of the most common mutations in Cystic Fibrosis (CF) patients is the deletion of the amino acid phenylalanine at position 508. This mutation causes both the protein trafficking defect and an early degradation. Over time, small molecules, called correctors, capable of increasing the amount of mutated channel in the plasma membrane and causing an increase in its transport activity have been developed. This study shows that incubating in vitro cells permanently transfected with the mutated channel with the correctors VX809, VX661 and Corr4a, and the combination of VX809 and Corr4a, a recovery of anion transport activity is observed. Interestingly, the permeability of bicarbonate increases in the cells containing corrected p.F508del CFTR channels is greater than the increase of the halide permeability. These different increases of the permeability of bicarbonate and halides are consistent with the concept that the structural conformation of the pore of the corrector-rescued p.F508del channels would be different than the normal wild type CFTR protein.
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9
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An organoid model to assay the role of CFTR in the human epididymis epithelium. Cell Tissue Res 2020; 381:327-336. [PMID: 32377875 DOI: 10.1007/s00441-020-03208-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/20/2020] [Indexed: 12/12/2022]
Abstract
Organoid cultures derived from primary human tissues facilitate the study of disease processes and the development of new therapeutics. Most men with cystic fibrosis (CF) are infertile due to defects in the epididymis and vas deferens; however, the causative mechanisms are still unclear. We used human epididymis epithelial cell (HEE) organoids and polarized HEE cell cultures to assay the CF transmembrane conductance regulator (CFTR) in the human epididymis. 3D HEE organoids and polarized 2D HEE cell cultures on membrane inserts were established from human caput epididymis. Single-cell RNA sequencing (scRNA-seq) was performed to map cell type-specific gene expression in the organoids. Using forskolin (FSK) to activate CFTR and inhibitor CFTRinh172 to block its activity, we assessed how CFTR contributes to organoid swelling and epithelial barrier function. The scRNA-seq data showed key caput epididymis cell types present in HEE organoid cultures. FSK at 10 μM induced HEE organoid swelling by 20% at 16 h, while 5 and 10 μM CFTRinh172 treatment significantly reduced HEE organoid size. In transepithelial resistance (TER) measurements, FSK reduced TER, while inhibition of CFTR increased TER; also, depletion of CFTR with specific siRNAs significantly increased TER. FSK treatment significantly increased the flux of 4-kDa but not 70-kDa dextran, suggesting activation of CFTR mainly enhances transcellular diffusion. We have demonstrated that CFTR contributes to the maintenance of HEE cell TER and that cultured HEE organoids are a useful model to investigate human epididymis function. These results facilitate progress in elucidating how CFTR-dependent cellular processes impair fertility in CF.
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10
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A Novel Genetically Encoded Single Use Sensory Cellular Test System Measures Bicarbonate Concentration Changes in Living Cells. SENSORS 2020; 20:s20061570. [PMID: 32168979 PMCID: PMC7146495 DOI: 10.3390/s20061570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 12/17/2022]
Abstract
Bicarbonate plays a central role in human physiology from cellular respiration to pH homeostasis. However, so far, the measurement of bicarbonate concentration changes in living cells has only been possible by measuring intracellular pH changes. In this article, we report the development of a genetically encoded pH-independent fluorescence-based single-use sensory cellular test system for monitoring intracellular bicarbonate concentration changes in living cells. We describe the usefulness of the developed biosensor in characterizing the bicarbonate transport activities of anionophores-small molecules capable of facilitating the membrane permeation of this anion. We also demonstrate the ability of the bicarbonate sensory cellular test system to measure intracellular bicarbonate concentration changes in response to activation and specific inhibition of wild-type human CFTR protein when co-expressed with the bicarbonate sensing and reporting units in living cells. A valuable benefit of the bicarbonate sensory cellular test system could be the screening of novel anionophore library compounds for bicarbonate transport activity with efficiencies close to the natural anion channel CFTR, which is not functional in the respiratory epithelia of cystic fibrosis patients.
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Stephens CE, Whittamore JM, Hatch M. 125 Iodide as a surrogate tracer for epithelial chloride transport by the mouse large intestine in vitro. Exp Physiol 2019; 104:334-344. [PMID: 30615234 PMCID: PMC6397055 DOI: 10.1113/ep087445] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/02/2019] [Indexed: 12/25/2022]
Abstract
NEW FINDINGS What is the central question of this study? The tracer 36 Cl- , currently used to measure transepithelial Cl- fluxes, has become prohibitively expensive, threatening its future use. 125 Iodide, previously validated alongside 36 Cl- as a tracer of Cl- efflux by cells, has not been tested as a surrogate for 36 Cl- across epithelia. What is the main finding and its importance? We demonstrate that 125 I- can serve as an inexpensive replacement for measuring Cl- transport across mouse large intestine, tracking Cl- transport in response to cAMP stimulation (inducing Cl- secretion) in the presence and absence of the main gastrointestinal Cl- -HCO3- exchanger, DRA. ABSTRACT Chloride transport is important for driving fluid secretion and absorption by the large intestine, with dysregulation resulting in diarrhoea-associated pathologies. The radioisotope 36 Cl- has long been used as a tracer to measure epithelial Cl- transport but is prohibitively expensive. 125 Iodide has been used as an alternative to 36 Cl- in some transport assays but has never been validated as an alternative for tracing bidirectional transepithelial Cl- fluxes. The goal of this study was to validate 125 I- as an alternative to 36 Cl- for measurement of Cl- transport by the intestine. Simultaneous fluxes of 36 Cl- and 125 I- were measured across the mouse caecum and distal colon. Net Cl- secretion was induced by the stimulation of cAMP with a cocktail of forskolin (FSK) and 3-isobutyl-1-methylxanthine (IBMX). Unidirectional fluxes of 125 I- correlated well with 36 Cl- fluxes after cAMP-induced net Cl- secretion, occurring predominantly through a reduction in the absorptive mucosal-to-serosal Cl- flux rather than by stimulation of the secretory serosal-to-mucosal Cl- flux. Correlations between 125 I- fluxes and 36 Cl- fluxes were maintained in epithelia from mice lacking DRA (Slc26a3), the main Cl- -HCO3- exchanger responsible for Cl- absorption by the large intestine. Lower rates of Cl- and I- absorption in the DRA knockout intestine suggest that DRA might have a previously unrecognized role in iodide uptake. This study validates that 125 I- traces transepithelial Cl- fluxes across the mouse large intestine, provides insights into the mechanism of net Cl- secretion and suggests that DRA might be involved in intestinal iodide absorption.
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Affiliation(s)
- Christine E Stephens
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Jonathan M Whittamore
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Marguerite Hatch
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
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Perniss A, Preiss K, Nier M, Althaus M. Hydrogen sulfide stimulates CFTR in Xenopus oocytes by activation of the cAMP/PKA signalling axis. Sci Rep 2017; 7:3517. [PMID: 28615646 PMCID: PMC5471219 DOI: 10.1038/s41598-017-03742-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 05/05/2017] [Indexed: 12/27/2022] Open
Abstract
Hydrogen sulfide (H2S) has been recognized as a signalling molecule which affects the activity of ion channels and transporters in epithelial cells. The cystic fibrosis transmembrane conductance regulator (CFTR) is an epithelial anion channel and a key regulator of electrolyte and fluid homeostasis. In this study, we investigated the regulation of CFTR by H2S. Human CFTR was heterologously expressed in Xenopus oocytes and its activity was electrophysiologically measured by microelectrode recordings. The H2S-forming sulphur salt Na2S as well as the slow-releasing H2S-liberating compound GYY4137 increased transmembrane currents of CFTR-expressing oocytes. Na2S had no effect on native, non-injected oocytes. The effect of Na2S was blocked by the CFTR inhibitor CFTR_inh172, the adenylyl cyclase inhibitor MDL 12330A, and the protein kinase A antagonist cAMPS-Rp. Na2S potentiated CFTR stimulation by forskolin, but not that by IBMX. Na2S enhanced CFTR stimulation by membrane-permeable 8Br-cAMP under inhibition of adenylyl cyclase-mediated cAMP production by MDL 12330A. These data indicate that H2S activates CFTR in Xenopus oocytes by inhibiting phosphodiesterase activity and subsequent stimulation of CFTR by cAMP-dependent protein kinase A. In epithelia, an increased CFTR activity may correspond to a pro-secretory response to H2S which may be endogenously produced by the epithelium or H2S-generating microflora.
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Affiliation(s)
- Alexander Perniss
- Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany.,Institute for Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany
| | - Kathrin Preiss
- Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany
| | - Marcel Nier
- Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany
| | - Mike Althaus
- Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany. .,School of Biology, Newcastle University, Newcastle upon Tyne, United Kingdom.
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13
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Zając M, Lewenstam A, Dolowy K. Multi-electrode system for measurement of transmembrane ion-fluxes through living epithelial cells. Bioelectrochemistry 2017. [PMID: 28633068 DOI: 10.1016/j.bioelechem.2017.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cystic Fibrosis (CF) is the most common fatal human genetic disease. It is caused by the defect in a single anion channel protein which affects ion and water transport across the epithelial tissue. A flat multi-electrode platform of diameter 12mm, allowing for measurement of four ions: sodium, potassium, hydrogen and chloride by exchangeable/replaceable ion-selective electrodes is described. The measurement is possible owing to the architecture of the platform which accommodates all the electrodes and inlets/outlets. The platform fits to the cup and operates in a small volume of the solution bathing the living epithelial cell layer (membrane) deposited on a porous support of the cup, which allows for effective monitoring of ion concentration changes. By applying two multi-electrode platforms, it is possible to measure the ion transmembrane fluxes. The inlet and outlet tubes in the platforms allow for on-fly change of the calibrants, ion-concentration changes and ion channel blockers. Using different ion-concentration gradients and blockers of ion-transporting molecules we show for the first time that sodium ions flow from the basolateral to apical face of the cell monolayer via a paracellular route and return also via a transcellular one, while chloride anions are transported back and forth exclusively via a transcellular route.
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Affiliation(s)
- Mirosław Zając
- Warsaw University of Life Sciences - SGGW, Department of Biophysics, 159 Nowoursynowska St., 02-776 Warsaw, Poland
| | - Andrzej Lewenstam
- Åbo Akademi University, Centre for Process Analytical Chemistry and Sensor Technology (ProSens), Johan Gadolin Process Chemistry Centre, Biskopsgatan 8, 20500 Åbo-Turku, Finland; AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Mickiewicza 30, 30-059 Krakow, Poland.
| | - Krzysztof Dolowy
- Warsaw University of Life Sciences - SGGW, Department of Biophysics, 159 Nowoursynowska St., 02-776 Warsaw, Poland
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Canella R, Martini M, Borriello R, Cavicchio C, Muresan XM, Benedusi M, Cervellati F, Valacchi G. Modulation of Chloride Currents in Human Lung Epithelial Cells Exposed to Exogenous Oxidative Stress. J Cell Physiol 2017; 232:1817-1825. [DOI: 10.1002/jcp.25705] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/22/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Rita Canella
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Marta Martini
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Roberta Borriello
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Carlotta Cavicchio
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Ximena M. Muresan
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Mascia Benedusi
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Franco Cervellati
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
| | - Giuseppe Valacchi
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara Italy
- Department of Animal Science; North Carolina State University; PHHI NC Research Campus; Kannapolis North Carolina
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Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel expressed in the apical membrane of epithelia. Mutations in the CFTR gene are the cause of cystsic fibrosis. CFTR is the only ABC-protein that constitutes an ion channel pore forming subunit. CFTR gating is regulated in complex manner as phosphorylation is mandatory for channel activity and gating is directly regulated by binding of ATP to specific intracellular sites on the CFTR protein. This review covers our current understanding on the gating mechanism in CFTR and illustrates the relevance of alteration of these mechanisms in the onset of cystic fibrosis.
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Affiliation(s)
- Oscar Moran
- Istituto di Biofisica, CNR. Via De Marini, 6, 16149, Genoa, Italy.
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16
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Leung GKC, Ying D, Mak CCY, Chen XY, Xu W, Yeung KS, Wong WL, Chu YWY, Mok GTK, Chau CSK, McLuskey J, Ong WPT, Leong HY, Chan KYK, Yang W, Chen JH, Li AM, Sham PC, Lau YL, Chung BHY, Lee SL. CFTR founder mutation causes protein trafficking defects in Chinese patients with cystic fibrosis. Mol Genet Genomic Med 2016; 5:40-49. [PMID: 28116329 PMCID: PMC5241212 DOI: 10.1002/mgg3.258] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 10/16/2016] [Accepted: 10/19/2016] [Indexed: 12/22/2022] Open
Abstract
Background Cystic fibrosis (CF) is a rare condition in Asians. Since 1985, only about 30 Chinese patients have been reported with molecular confirmation. Method Using our in‐house next‐generation sequencing (NGS) pipeline for childhood bronchiectasis, we identified disease‐causing CFTR mutations in CF patients in Hong Kong. After identifying p.I1023R in multiple patients, haplotype analysis was performed with genome‐wide microarray to ascertain the likelihood of this being a founder mutation. We also assessed the processing and gating activity of the mutant protein by Western hybridization and patch‐clamp test. Results Molecular diagnoses were confirmed in four patients, three of whom shared a missense mutation: CFTR:c.3068T>G:p.I1023R. The results suggested that p.I1023R is a founder mutation in southern Han Chinese. In addition, the processing and gating activity of the mutant protein was assessed by gel electrophoresis and a patch‐clamp test. The mutant protein exhibited trafficking defects, suggesting that the dysfunction is caused by reduced cell surface expression of the fully glycosylated proteins. Conclusion Together with other previously reported mutations, the specific founder mutation presented herein suggests a unique CFTR mutation spectrum in the southern Chinese populations, and this finding has vital implications for improving molecular testing and mutation‐specific treatments for Chinese patients with CF.
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Affiliation(s)
- Gordon K C Leung
- Department of Paediatrics and Adolescent Medicine LKS Faculty of Medicine The University of Hong Kong Hong Kong Hong Kong
| | - Dingge Ying
- Department of Psychiatry LKS Faculty of Medicine The University of Hong Kong Hong Kong Hong Kong
| | - Christopher C Y Mak
- Department of Paediatrics and Adolescent Medicine LKS Faculty of Medicine The University of Hong Kong Hong Kong Hong Kong
| | - Xin-Ying Chen
- HKU Shenzhen Institute of Research and Innovation School of Biomedical Sciences The University of Hong Kong Hong Kong Hong Kong
| | - Weiyi Xu
- HKU Shenzhen Institute of Research and Innovation School of Biomedical Sciences The University of Hong Kong Hong Kong Hong Kong
| | - Kit-San Yeung
- Department of Paediatrics and Adolescent Medicine LKS Faculty of Medicine The University of Hong Kong Hong Kong Hong Kong
| | - Wai-Lap Wong
- Department of Paediatrics and Adolescent Medicine LKS Faculty of Medicine The University of Hong Kong Hong Kong Hong Kong
| | - Yoyo W Y Chu
- Department of Paediatrics and Adolescent Medicine LKS Faculty of Medicine The University of Hong Kong Hong Kong Hong Kong
| | - Gary T K Mok
- Department of Paediatrics and Adolescent Medicine LKS Faculty of Medicine The University of Hong Kong Hong Kong Hong Kong
| | - Christy S K Chau
- Department of Paediatrics and Adolescent Medicine Queen Mary Hospital Hong Kong Hong Kong
| | | | - Winnie P T Ong
- Department of Genetics Kuala Lumpur Hospital Kuala Lumpur Malaysia
| | - Huey-Yin Leong
- Department of Genetics Kuala Lumpur Hospital Kuala Lumpur Malaysia
| | - Kelvin Y K Chan
- Department of Obstetrics and Gynaecology Tsan Yuk Hospital Hong Kong Hong Kong
| | - Wanling Yang
- Department of Paediatrics and Adolescent Medicine LKS Faculty of Medicine The University of Hong Kong Hong Kong Hong Kong
| | - Jeng-Haur Chen
- HKU Shenzhen Institute of Research and Innovation School of Biomedical Sciences The University of Hong Kong Hong Kong Hong Kong
| | - Albert M Li
- Department of Paediatrics Faculty of Medicine The Chinese University of Hong Kong Hong Kong Hong Kong
| | - Pak C Sham
- Department of Psychiatry LKS Faculty of Medicine The University of Hong Kong Hong Kong Hong Kong
| | - Yu-Lung Lau
- Department of Paediatrics and Adolescent MedicineLKS Faculty of MedicineThe University of Hong KongHong KongHong Kong; Department of Paediatrics and Adolescent MedicineQueen Mary HospitalHong KongHong Kong
| | - Brian H Y Chung
- Department of Paediatrics and Adolescent MedicineLKS Faculty of MedicineThe University of Hong KongHong KongHong Kong; Department of Paediatrics and Adolescent MedicineQueen Mary HospitalHong KongHong Kong; Department of Paediatrics and Adolescent MedicineThe Duchess of Kent Children's Hospital at Sandy BayHong Kong
| | - So-Lun Lee
- Department of Paediatrics and Adolescent MedicineLKS Faculty of MedicineThe University of Hong KongHong KongHong Kong; Department of Paediatrics and Adolescent MedicineQueen Mary HospitalHong KongHong Kong; Department of Paediatrics and Adolescent MedicineThe Duchess of Kent Children's Hospital at Sandy BayHong Kong
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Zwick M, Esposito C, Hellstern M, Seelig A. How Phosphorylation and ATPase Activity Regulate Anion Flux though the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). J Biol Chem 2016; 291:14483-98. [PMID: 27226582 DOI: 10.1074/jbc.m116.721415] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Indexed: 01/25/2023] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR, ABCC7), mutations of which cause cystic fibrosis, belongs to the ATP-binding cassette (ABC) transporter family and works as a channel for small anions, such as chloride and bicarbonate. Anion channel activity is known to depend on phosphorylation by cAMP-dependent protein kinase A (PKA) and CFTR-ATPase activity. Whereas anion channel activity has been extensively investigated, phosphorylation and CFTR-ATPase activity are still poorly understood. Here, we show that the two processes can be measured in a label-free and non-invasive manner in real time in live cells, stably transfected with CFTR. This study reveals three key findings. (i) The major contribution (≥90%) to the total CFTR-related ATP hydrolysis rate is due to phosphorylation by PKA and the minor contribution (≤10%) to CFTR-ATPase activity. (ii) The mutant CFTR-E1371S that is still conductive, but defective in ATP hydrolysis, is not phosphorylated, suggesting that phosphorylation requires a functional nucleotide binding domain and occurs in the post-hydrolysis transition state. (iii) CFTR-ATPase activity is inversely related to CFTR anion flux. The present data are consistent with a model in which CFTR is in a closed conformation with two ATPs bound. The open conformation is induced by ATP hydrolysis and corresponds to the post-hydrolysis transition state that is stabilized by phosphorylation and binding of chloride channel potentiators.
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Affiliation(s)
- Matthias Zwick
- From the Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Cinzia Esposito
- From the Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Manuel Hellstern
- From the Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
| | - Anna Seelig
- From the Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
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18
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Chen L, Yu B, Zhang Y, Gao X, Zhu L, Ma T, Yang H. Bioactivity-guided fractionation of an antidiarrheal Chinese herb Rhodiola kirilowii (Regel) Maxim reveals (-)-epicatechin-3-gallate and (-)-epigallocatechin-3-gallate as inhibitors of cystic fibrosis transmembrane conductance regulator. PLoS One 2015; 10:e0119122. [PMID: 25747701 PMCID: PMC4352019 DOI: 10.1371/journal.pone.0119122] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 01/22/2015] [Indexed: 02/02/2023] Open
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) is the principal apical route for transepithelial fluid transport induced by enterotoxin. Inhibition of CFTR has been confirmed as a pharmaceutical approach for the treatment of secretory diarrhea. Many traditional Chinese herbal medicines, like Rhodiola kirilowii (Regel) Maxim, have long been used for the treatment of secretory diarrhea. However, the active ingredients responsible for their therapeutic effectiveness remain unknown. The purpose of this study is to identify CFTR inhibitors from Rhodiola kirilowii (Regel) Maxim via bioactivity-directed isolation strategy. We first identified fractions of Rhodiola kirilowii (Regel) Maxim that inhibited CFTR Cl- channel activity. Further bioactivity-directed fractionation led to the identification of (-)–epigallocatechin-3-gallate (EGCG) as CFTR Cl- channel inhibitor. Analysis of 5 commercially available EGCG analogs including (+)–catechins (C), (-)–epicatechin (EC), (-)–epigallocatechin (EGC), (-)–epicatechin-3-gallate (ECG) and EGCG revealed that ECG also had CFTR inhibitory activity. EGCG dose-dependently and reversibly inhibited CFTR Cl- channel activity in transfected FRT cells with an IC50 value around 100 μM. In ex vivo studies, EGCG and ECG inhibited CFTR-mediated short-circuit currents in isolated rat colonic mucosa in a dose-dependent manner. In an intestinal closed-loop model in mice, intraluminal application of EGCG (10 μg) and ECG (10 μg) significantly reduced cholera toxin-induced intestinal fluid secretion. CFTR Cl- channel is a molecular target of natural compounds EGCG and ECG. CFTR inhibition may account, at least in part, for the antidiarrheal activity of Rhodiola kirilowii (Regel) Maxim. EGCG and ECG could be new lead compounds for development of CFTR-related diseases such as secretory diarrhea.
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Affiliation(s)
- Lei Chen
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116029, P. R. China
| | - Bo Yu
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116029, P. R. China
| | - Yaofang Zhang
- College of Basic Medical Sciences, Dalian Medical University, Dalian, 116044, P. R. China
| | - Xin Gao
- School of Medicine, Yanbian University, Yanji, 133002, P. R. China
| | - Liang Zhu
- College of Basic Medical Sciences, Dalian Medical University, Dalian, 116044, P. R. China
| | - Tonghui Ma
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116029, P. R. China
- College of Basic Medical Sciences, Dalian Medical University, Dalian, 116044, P. R. China
| | - Hong Yang
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116029, P. R. China
- * E-mail:
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Boucherle B, Bertrand J, Maurin B, Renard BL, Fortuné A, Tremblier B, Becq F, Norez C, Décout JL. A new 9-alkyladenine-cyclic methylglyoxal diadduct activates wt- and F508del-cystic fibrosis transmembrane conductance regulator (CFTR) in vitro and in vivo. Eur J Med Chem 2014; 83:455-65. [PMID: 24992073 DOI: 10.1016/j.ejmech.2014.06.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 06/12/2014] [Accepted: 06/13/2014] [Indexed: 01/28/2023]
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) is the main chloride channel present in the apical membrane of epithelial cells and the F508 deletion (F508del-CFTR) in the CF gene is the most common cystic fibrosis-causing mutation. In the search for a pharmacotherapy of cystic fibrosis caused by the F508del-CFTR, a bi-therapy could be developed associating a corrector of F508del-CFTR trafficking and an activator of the channel activity of CFTR. Here, we report on the synthesis of 9-alkyladenine derivatives analogues of our previously discovered activator of wt-CFTR and F508del-CFTR, GPact-11a, and the identification of a new activator of these channels, GPact-26a, through various flux assays on human airway epithelial CF and non-CF cell lines and in vivo measurement of rat salivary secretion. This study reveals that the possible modifications of the side chain introduced at the N9 position of the main pharmacophore are highly limited since only an allyl group can replace the propyl side chain present in GPact-11a to lead to a strong activation of wt-CFTR in CHO cells. Docking simulations of the synthesised compounds and of four described modulators performed using a 3D model of the wt-type CFTR protein suggest five possible binding sites located at the interface of the nucleotide binding domains NBD1/NBD2. However, the docking study did not allow the differentiation between active and non-active compounds.
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Affiliation(s)
- Benjamin Boucherle
- Université Grenoble Alpes, Joseph Fourier/CNRS, UMR 5063, Département de Pharmacochimie Moléculaire, 470 rue de la Chimie, F-38041 Grenoble, France
| | - Johanna Bertrand
- Université de Poitiers/CNRS, Laboratoire Signalisation et Transports Ioniques Membranaires, 1 rue Georges Bonnet, F-86022 Poitiers, France
| | - Bruno Maurin
- Université Grenoble Alpes, Joseph Fourier/CNRS, UMR 5063, Département de Pharmacochimie Moléculaire, 470 rue de la Chimie, F-38041 Grenoble, France
| | - Brice-Loïc Renard
- Université Grenoble Alpes, Joseph Fourier/CNRS, UMR 5063, Département de Pharmacochimie Moléculaire, 470 rue de la Chimie, F-38041 Grenoble, France
| | - Antoine Fortuné
- Université Grenoble Alpes, Joseph Fourier/CNRS, UMR 5063, Département de Pharmacochimie Moléculaire, 470 rue de la Chimie, F-38041 Grenoble, France
| | - Brice Tremblier
- Université de Poitiers/CNRS, Laboratoire Signalisation et Transports Ioniques Membranaires, 1 rue Georges Bonnet, F-86022 Poitiers, France
| | - Frédéric Becq
- Université de Poitiers/CNRS, Laboratoire Signalisation et Transports Ioniques Membranaires, 1 rue Georges Bonnet, F-86022 Poitiers, France
| | - Caroline Norez
- Université de Poitiers/CNRS, Laboratoire Signalisation et Transports Ioniques Membranaires, 1 rue Georges Bonnet, F-86022 Poitiers, France
| | - Jean-Luc Décout
- Université Grenoble Alpes, Joseph Fourier/CNRS, UMR 5063, Département de Pharmacochimie Moléculaire, 470 rue de la Chimie, F-38041 Grenoble, France.
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Vijftigschild LAW, van der Ent CK, Beekman JM. A novel fluorescent sensor for measurement of CFTR function by flow cytometry. Cytometry A 2013; 83:576-84. [DOI: 10.1002/cyto.a.22275] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 01/10/2013] [Accepted: 02/07/2013] [Indexed: 11/07/2022]
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21
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Brodlie M, McKean MC, Johnson GE, Perry JD, Nicholson A, Verdon B, Gray MA, Dark JH, Pearson JP, Fisher AJ, Corris PA, Lordan J, Ward C. Primary bronchial epithelial cell culture from explanted cystic fibrosis lungs. Exp Lung Res 2010; 36:101-10. [PMID: 20205595 DOI: 10.3109/01902140903165265] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Lung disease is responsible for more than 95% of morbidity and mortality in cystic fibrosis. The exact pathogenesis of cystic fibrosis lung disease remains poorly understood. Experimental models are therefore vital for use in research. Animal models and immortalized cell lines both have inherent limitations. Explanted lungs removed from people with cystic fibrosis at the time of transplantation represent a potentially valuable but technically and logistically challenging source of primary cystic fibrosis bronchial epithelial cells. In this study, pieces of segmental bronchus from explanted lungs were treated with patient-specific antimicrobials prior to isolation of bronchial epithelial cells. Cultured cells were characterized by their morphology under light microscopy, cytokeratin and hematoxylin-eosin staining, and electrophysiological profile. Primary bronchial epithelial cells were successfully cultured from 15 of 22 patients attempted. The cells exhibited typical epithelial morphology, staining for cytokeratin, lack of responsiveness to forskolin treatment, and remained viable after storage in liquid nitrogen. Seven unsuccessful cultures failed due to early infection with bacteria known to colonize the airways pretransplant. The results show that primary bronchial epithelial cell culture is possible from explanted cystic fibrosis lungs. This provides an important cellular model to elucidate the pathogenic mechanisms in cystic fibrosis lung disease and to investigate potential therapeutic targets.
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Affiliation(s)
- Malcolm Brodlie
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.
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22
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Moran O. Model of the cAMP activation of chloride transport by CFTR channel and the mechanism of potentiators. J Theor Biol 2009; 262:73-9. [PMID: 19766125 DOI: 10.1016/j.jtbi.2009.08.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 08/12/2009] [Accepted: 08/22/2009] [Indexed: 11/30/2022]
Abstract
Mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis, a hereditary lethal disease. CFTR is a chloride channel expressed in the apical membrane of epithelia. It is activated by cAMP dependent phosphorylation and gated by the binding of ATP. The impaired chloride transport of some types of cystic fibrosis mutations could be pharmacologically solved by the use of chemical compounds called potentiators. Here it is undertaken the construction of a model of the CFTR activation pathways, and the possible modification produced by a potentiator application. The model yields a novel mechanism for the potentiator action, describing the activatory and inhibitory activities on two different positions in the CFTR activation pathway.
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