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Thakur S, Ankita, Dash S, Verma R, Kaur C, Kumar R, Mazumder A, Singh G. Understanding CFTR Functionality: A Comprehensive Review of Tests and Modulator Therapy in Cystic Fibrosis. Cell Biochem Biophys 2024; 82:15-34. [PMID: 38048024 DOI: 10.1007/s12013-023-01200-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/13/2023] [Indexed: 12/05/2023]
Abstract
Cystic fibrosis is a genetic disorder inherited in an autosomal recessive manner. It is caused by a mutation in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene on chromosome 7, which leads to abnormal regulation of chloride and bicarbonate ions in cells that line organs like the lungs and pancreas. The CFTR protein plays a crucial role in regulating chloride ion flow, and its absence or malfunction causes the production of thick mucus that affects several organs. There are more than 2000 identified mutations that are classified into seven categories based on their dysfunction mechanisms. In this article, we have conducted a thorough examination and consolidation of the diverse array of tests essential for the quantification of CFTR functionality. Furthermore, we have engaged in a comprehensive discourse regarding the recent advancements in CFTR modulator therapy, a pivotal approach utilized for the management of cystic fibrosis, alongside its concomitant relevance in evaluating CFTR functionality.
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Affiliation(s)
- Shorya Thakur
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Ankita
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Shubham Dash
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Rupali Verma
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Charanjit Kaur
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Rajesh Kumar
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Avijit Mazumder
- Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, UP, India
| | - Gurvinder Singh
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India.
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2
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Mutyam V, Sharma J, Li Y, Peng N, Chen J, Tang LP, Falk Libby E, Singh AK, Conrath K, Rowe SM. Novel Correctors and Potentiators Enhance Translational Readthrough in CFTR Nonsense Mutations. Am J Respir Cell Mol Biol 2021; 64:604-616. [PMID: 33616476 DOI: 10.1165/rcmb.2019-0291oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Premature-termination codons (PTCs) in CFTR (cystic fibrosis [CF] transmembrane conductance regulator) result in nonfunctional CFTR protein and are the proximate cause of ∼11% of CF-causing alleles, for which no treatments exist. The CFTR corrector lumacaftor and the potentiator ivacaftor improve CFTR function with terminal PTC mutations and enhance the effect of readthrough agents. Novel correctors GLPG2222 (corrector 1 [C1]), GLPG3221 (corrector 2 [C2]), and potentiator GLPG1837 compare favorably with lumacaftor and ivacaftor in vitro. Here, we evaluated the effect of correctors C1a and C2a (derivatives of C1 and C2) and GLPG1837 alone or in combination with the readthrough compound G418 on CFTR function using heterologous Fischer rat thyroid (FRT) cells, the genetically engineered human bronchial epithelial (HBE) 16HBE14o- cell lines, and primary human cells with PTC mutations. In FRT lines pretreated with G418, GLPG1837 elicited dose-dependent increases in CFTR activity that exceeded those from ivacaftor in FRT-W1282X and FRT-R1162X cells. A three-mechanism strategy consisting of G418, GLPG1837, and two correctors (C1a + C2a) yielded the greatest functional improvements in FRT and 16HBE14o- PTC variants, noting that correction and potentiation without readthrough was sufficient to stimulate CFTR activity for W1282X cells. GLPG1837 + C1a + C2a restored substantial function in G542X/F508del HBE cells and restored even more function for W1282X/F508del cells, largely because of the corrector/potentiator effect, with no additional benefit from G418. In G542X/R553X or R1162X/R1162X organoids, enhanced forskolin-induced swelling was observed with G418 + GLPG1837 + C1a + C2a, although GLPG1837 + C1a + C2a alone was sufficient to improve forskolin-induced swelling in W1282X/W1282X organoids. Combination of CFTR correctors, potentiators, and readthrough compounds augments the functional repair of CFTR nonsense mutations, indicating the potential for novel correctors and potentiators to restore function to truncated W1282X CFTR.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Steven M Rowe
- Department of Medicine.,Department of Pediatrics.,Department of Cell Developmental and Integrative Biology, and.,Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama
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3
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Rathner A, Rathner P, Friedrich A, Wießner M, Kitzler CM, Schernthaner J, Karl T, Krauß J, Lottspeich F, Mewes W, Hintner H, Bauer JW, Breitenbach M, Müller N, Breitenbach-Koller H, von Hagen J. Drug Development for Target Ribosomal Protein rpL35/uL29 for Repair of LAMB3R635X in Rare Skin Disease Epidermolysis Bullosa. Skin Pharmacol Physiol 2021; 34:167-182. [PMID: 33823521 DOI: 10.1159/000513260] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/22/2020] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Epidermolysis bullosa (EB) describes a family of rare genetic blistering skin disorders. Various subtypes are clinically and genetically heterogeneous, and a lethal postpartum form of EB is the generalized severe junctional EB (gs-JEB). gs-JEB is mainly caused by premature termination codon (PTC) mutations in the skin anchor protein LAMB3 (laminin subunit beta-3) gene. The ribosome in majority of translational reads of LAMB3PTC mRNA aborts protein synthesis at the PTC signal, with production of a truncated, nonfunctional protein. This leaves an endogenous readthrough mechanism needed for production of functional full-length Lamb3 protein albeit at insufficient levels. Here, we report on the development of drugs targeting ribosomal protein L35 (rpL35), a ribosomal modifier for customized increase in production of full-length Lamb3 protein from a LAMB3PTC mRNA. METHODS Molecular docking studies were employed to identify small molecules binding to human rpL35. Molecular determinants of small molecule binding to rpL35 were further characterized by titration of the protein with these ligands as monitored by nuclear magnetic resonance (NMR) spectroscopy in solution. Changes in NMR chemical shifts were used to map the docking sites for small molecules onto the 3D structure of the rpL35. RESULTS Molecular docking studies identified 2 FDA-approved drugs, atazanavir and artesunate, as candidate small-molecule binders of rpL35. Molecular interaction studies predicted several binding clusters for both compounds scattered throughout the rpL35 structure. NMR titration studies identified the amino acids participating in the ligand interaction. Combining docking predictions for atazanavir and artesunate with rpL35 and NMR analysis of rpL35 ligand interaction, one binding cluster located near the N-terminus of rpL35 was identified. In this region, the nonidentical binding sites for atazanavir and artesunate overlap and are accessible when rpL35 is integrated in its natural ribosomal environment. CONCLUSION Atazanavir and artesunate were identified as candidate compounds binding to ribosomal protein rpL35 and may now be tested for their potential to trigger a rpL35 ribosomal switch to increase production of full-length Lamb3 protein from a LAMB3PTC mRNA for targeted systemic therapy in treating gs-JEB.
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Affiliation(s)
- Adriana Rathner
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Petr Rathner
- Department of Biosciences, University of Salzburg, Salzburg, Austria
- Institute of Inorganic Chemistry, Johannes Kepler University, Linz, Austria
| | - Andreas Friedrich
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Michael Wießner
- Department of Biosciences, University of Salzburg, Salzburg, Austria
- Department of Allergology and Dermatology, University Hospital Salzburg, Salzburg, Austria
| | | | - Jan Schernthaner
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Thomas Karl
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Jan Krauß
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | | | - Werner Mewes
- TUM School of Life Sciences, Technical University of Munich, Munich, Germany
| | - Helmut Hintner
- Department of Biosciences, University of Salzburg, Salzburg, Austria
- Department of Allergology and Dermatology, University Hospital Salzburg, Salzburg, Austria
| | - Johann W Bauer
- Department of Biosciences, University of Salzburg, Salzburg, Austria
- Department of Allergology and Dermatology, University Hospital Salzburg, Salzburg, Austria
| | | | - Norbert Müller
- Institute of Inorganic Chemistry, Johannes Kepler University, Linz, Austria
- Institute of Organic Chemistry, Johannes Kepler University, Linz, Austria
- Faculty of Natural Sciences, University of South Bohemia, Ceske Budejovice, Czechia
| | | | - Jörg von Hagen
- Department of Life Science Engineering, Technische Hochschule Mittelhessen, Gießen, Germany
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Bardin E, Pastor A, Semeraro M, Golec A, Hayes K, Chevalier B, Berhal F, Prestat G, Hinzpeter A, Gravier-Pelletier C, Pranke I, Sermet-Gaudelus I. Modulators of CFTR. Updates on clinical development and future directions. Eur J Med Chem 2021; 213:113195. [PMID: 33524685 DOI: 10.1016/j.ejmech.2021.113195] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 12/19/2022]
Abstract
Cystic fibrosis (CF) is the most frequent life-limiting autosomal recessive disorder in the Caucasian population. It is due to mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. Current symptomatic CF therapies, which treat the downstream consequences of CFTR mutations, have increased survival. Better knowledge of the CFTR protein has enabled pharmacologic therapy aiming to restore mutated CFTR expression and function. These CFTR "modulators" have revolutionised the CF therapeutic landscape, with the potential to transform prognosis for a considerable number of patients. This review provides a brief summary of their mechanism of action and presents a thorough review of the results obtained from clinical trials of CFTR modulators.
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Affiliation(s)
| | - Alexandra Pastor
- LCBPT, UMR CNRS 8601, Paris, France; Université de Paris, Paris, France
| | - Michaela Semeraro
- Centre d'Investigation Clinique, Unité de Recherche Clinique-CIC P1419, Hôpital Necker Enfants Malades, Université de Paris, Paris, France
| | - Anita Golec
- Institut Necker Enfants Malades. INSERM U1151, Paris, France
| | - Kate Hayes
- Clinical Trial Network, European Cystic Fibrosis Society, Belfast, Ireland
| | | | - Farouk Berhal
- LCBPT, UMR CNRS 8601, Paris, France; Université de Paris, Paris, France
| | - Guillaume Prestat
- LCBPT, UMR CNRS 8601, Paris, France; Université de Paris, Paris, France
| | | | | | - Iwona Pranke
- Institut Necker Enfants Malades. INSERM U1151, Paris, France
| | - Isabelle Sermet-Gaudelus
- Institut Necker Enfants Malades. INSERM U1151, Paris, France; Université de Paris, Paris, France; Clinical Trial Network, European Cystic Fibrosis Society, Belfast, Ireland; Centre de Référence Maladies Rares, Mucoviscidose et Maladies de CFTR, Hôpital Necker Enfants Malades, Paris, France; European Respiratory Network Lung, Paris, France.
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5
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Rang C, Keating D, Wilson J, Kotsimbos T. Re-imagining cystic fibrosis care: next generation thinking. Eur Respir J 2020; 55:13993003.02443-2019. [PMID: 32139465 DOI: 10.1183/13993003.02443-2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 02/20/2020] [Indexed: 12/26/2022]
Abstract
Cystic fibrosis (CF) is a common multi-system genetically inherited condition, predominately found in individuals of Caucasian decent. Since the identification of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene in 1989, and the subsequent improvement in understanding of CF pathophysiology, significant increases in life-expectancy have followed. Initially this was related to improvements in the management and systems of care for treating the various affected organ systems. These cornerstone treatments are still essential for CF patients born today. However, over the last decade, the major advance has been in therapies that target the resultant genetic defect: the dysfunctional CFTR protein. Small molecule agents that target this dysfunctional protein via a variety of mechanisms have led to lung function improvements, reductions in pulmonary exacerbation rates and increases in weight and quality-of-life indices. As more patients receive these agents earlier and earlier in life, it is likely that general CF care will increasingly pivot around these specific therapies, although it is also likely that effects other than those identified in the initial trials will be discovered and need to be managed. Despite great excitement for modulator therapies, they are unlikely to be suitable or available for all; whether this is due to a lack of availability for specific CFTR mutations, drug-reactions or the health economic set-up in certain countries. Nevertheless, the CF community must be applauded for its ongoing focus on research and development for this life-limiting disease. With time, personalised individualised therapy would ideally be the mainstay of CF care.
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Affiliation(s)
- Catherine Rang
- Cystic Fibrosis Service, Dept of Respiratory Medicine, Alfred Health, Melbourne, Australia
| | - Dominic Keating
- Cystic Fibrosis Service, Dept of Respiratory Medicine, Alfred Health, Melbourne, Australia.,Dept of Medicine, Monash University, Alfred Campus, Melbourne, Australia
| | - John Wilson
- Cystic Fibrosis Service, Dept of Respiratory Medicine, Alfred Health, Melbourne, Australia.,Dept of Medicine, Monash University, Alfred Campus, Melbourne, Australia
| | - Tom Kotsimbos
- Cystic Fibrosis Service, Dept of Respiratory Medicine, Alfred Health, Melbourne, Australia.,Dept of Medicine, Monash University, Alfred Campus, Melbourne, Australia
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Xia S, Zhou C, Kalionis B, Shuang X, Ge H, Gao W. Combined Antioxidant, Anti-inflammaging and Mesenchymal Stem Cell Treatment: A Possible Therapeutic Direction in Elderly Patients with Chronic Obstructive Pulmonary Disease. Aging Dis 2020; 11:129-140. [PMID: 32010487 PMCID: PMC6961773 DOI: 10.14336/ad.2019.0508] [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: 02/28/2019] [Accepted: 05/08/2019] [Indexed: 12/19/2022] Open
Abstract
Chronic Obstructive Pulmonary Disease (COPD) is a worldwide health problem associated with high morbidity and mortality, especially in elderly patients. Aging functions include mitochondrial dysfunction, cell-to-cell information exchange, protein homeostasis and extracellular matrix dysregulation, which are closely related to chronic inflammatory response and oxidation-antioxidant imbalance in the pathogenesis of COPD. COPD displays distinct inflammaging features, including increased cellular senescence and oxidative stress, stem cell exhaustion, alterations in the extracellular matrix, reduced levels of endogenous anti-inflammaging molecules, and reduced autophagy. Given that COPD and inflammaging share similar general features, it is very important to identify the specific mechanisms of inflammaging, which involve oxidative stress, inflammation and lung mesenchymal stem cell function in the development of COPD, especially in elderly COPD patients. In this review, we highlight the studies relevant to COPD progression, and focus on mechanisms associated with inflammaging.
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Affiliation(s)
- Shijin Xia
- 1Shanghai Institute of Geriatrics, Huadong Hospital, Fudan University, Shanghai, China
| | - Changxi Zhou
- 2Department of Respiratory Medicine, The Second Medical Center of PLA General Hospital, Beijing, China
| | - Bill Kalionis
- 3Department of Maternal-Fetal Medicine Pregnancy Research Centre and University of Melbourne Department of Obstetrics and Gynaecology, Royal Women's Hospital, Parkville, Victoria, Australia
| | - Xiaoping Shuang
- 4Department of Cardiovascular Diseases, Xiangyang Hospital of Traditional Chinese Medicine, Xiangyang, Hubei, China
| | - Haiyan Ge
- 5Department of Pulmonary Diseases, Huadong Hospital, Fudan University, Shanghai, China
| | - Wen Gao
- 6Department of Thoracic Surgery, Huadong Hospital, Fudan University, Shanghai, China
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7
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Abstract
Cystic fibrosis (CF) is an autosomal recessive, inherited congenital disease caused by the mutation of the family autosomal CF gene, with cumulative exocrine secretion characterized by inflammation, tracheal remodeling, and mucus accumulation. With the development of modern medical technology, CF patients are living longer lives and receiving more and more treatments, including traditional drugs, physical therapy, and gene therapy. Exercise is widely used to prevent and treat metabolic diseases such as cardiovascular diseases, obesity, diabetes, and metabolic syndrome. Regular exercise is beneficial to aerobic capacity and lung health. Exercise therapy has been of great interest since people realized that CF can be affected by exercise. Exercise alone can be used as an ACT (airway clearance technique), which promotes the removal of mucosal cilia. Exercise therapy is more easily accepted by any society, which helps to normalize the lives of CF patients, rather than placing a psychological burden on them. In this chapter, we will review the latest research progress about exercise in CF.
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Affiliation(s)
- Shengguang Ding
- Department of Thoracic and Cardiovascular Surgery, The Second Affiliated Hospital of Nantong University, Nantong, China
| | - Chongjun Zhong
- Department of Thoracic and Cardiovascular Surgery, The Second Affiliated Hospital of Nantong University, Nantong, China
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8
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Bell SC, Mall MA, Gutierrez H, Macek M, Madge S, Davies JC, Burgel PR, Tullis E, Castaños C, Castellani C, Byrnes CA, Cathcart F, Chotirmall SH, Cosgriff R, Eichler I, Fajac I, Goss CH, Drevinek P, Farrell PM, Gravelle AM, Havermans T, Mayer-Hamblett N, Kashirskaya N, Kerem E, Mathew JL, McKone EF, Naehrlich L, Nasr SZ, Oates GR, O'Neill C, Pypops U, Raraigh KS, Rowe SM, Southern KW, Sivam S, Stephenson AL, Zampoli M, Ratjen F. The future of cystic fibrosis care: a global perspective. THE LANCET RESPIRATORY MEDICINE 2020; 8:65-124. [DOI: 10.1016/s2213-2600(19)30337-6] [Citation(s) in RCA: 351] [Impact Index Per Article: 87.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/19/2019] [Accepted: 08/14/2019] [Indexed: 02/06/2023]
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9
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Doiron JE, Le CA, Ody BK, Brace JB, Post SJ, Thacker NL, Hill HM, Breton GW, Mulder MJ, Chang S, Bridges TM, Tang L, Wang W, Rowe SM, Aller SG, Turlington M. Evaluation of 1,2,3-Triazoles as Amide Bioisosteres In Cystic Fibrosis Transmembrane Conductance Regulator Modulators VX-770 and VX-809. Chemistry 2019; 25:3662-3674. [PMID: 30650214 PMCID: PMC6469399 DOI: 10.1002/chem.201805919] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/14/2019] [Indexed: 12/25/2022]
Abstract
The 1,2,3-triazole has been successfully utilized as an amide bioisostere in multiple therapeutic contexts. Based on this precedent, triazole analogues derived from VX-809 and VX-770, prominent amide-containing modulators of the cystic fibrosis transmembrane conductance regulator (CFTR), were synthesized and evaluated for CFTR modulation. Triazole 11, derived from VX-809, displayed markedly reduced efficacy in F508del-CFTR correction in cellular TECC assays in comparison to VX-809. Surprisingly, triazole analogues derived from potentiator VX-770 displayed no potentiation of F508del, G551D, or WT-CFTR in cellular Ussing chamber assays. However, patch clamp analysis revealed that triazole 60 potentiates WT-CFTR similarly to VX-770. The efficacy of 60 in the cell-free patch clamp experiment suggests that the loss of activity in the cellular assay could be due to the inability of VX-770 triazole derivatives to reach the CFTR binding site. Moreover, in addition to the negative impact on biological activity, triazoles in both structural classes displayed decreased metabolic stability in human microsomes relative to the analogous amides. In contrast to the many studies that demonstrate the advantages of using the 1,2,3-triazole, these findings highlight the negative impacts that can arise from replacement of the amide with the triazole and suggest that caution is warranted when considering use of the 1,2,3-triazole as an amide bioisostere.
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Affiliation(s)
- Jake E. Doiron
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia 30165 (USA),
| | - Christina A. Le
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, Alabama 35205 (USA),
| | - Britton K. Ody
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia 30165 (USA),
| | - Jonathon B. Brace
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia 30165 (USA),
| | - Savannah J. Post
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia 30165 (USA),
| | - Nathan L. Thacker
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia 30165 (USA),
| | - Harrison M. Hill
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia 30165 (USA),
| | - Gary W. Breton
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia 30165 (USA),
| | - Matthew J. Mulder
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, Tennessee 37232 (USA)
| | - Sichen Chang
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, Tennessee 37232 (USA)
| | - Thomas M. Bridges
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, Tennessee 37232 (USA)
| | - Liping Tang
- Departments of Medicine and Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama 35205 (USA)
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35205 (USA)
| | - Wei Wang
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35205 (USA)
- Department of Cell, Development, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35205 (USA)
| | - Steven M. Rowe
- Departments of Medicine and Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama 35205 (USA)
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35205 (USA)
- Department of Cell, Development, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35205 (USA)
| | - Stephen G. Aller
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, Alabama 35205 (USA),
| | - Mark Turlington
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia 30165 (USA),
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10
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Pranke I, Golec A, Hinzpeter A, Edelman A, Sermet-Gaudelus I. Emerging Therapeutic Approaches for Cystic Fibrosis. From Gene Editing to Personalized Medicine. Front Pharmacol 2019; 10:121. [PMID: 30873022 PMCID: PMC6400831 DOI: 10.3389/fphar.2019.00121] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 01/31/2019] [Indexed: 12/13/2022] Open
Abstract
An improved understanding of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) protein structure and the consequences of CFTR gene mutations have allowed the development of novel therapies targeting specific defects underlying CF. Some strategies are mutation specific and have already reached clinical development; some strategies include a read-through of the specific premature termination codons (read-through therapies, nonsense mediated decay pathway inhibitors for Class I mutations); correction of CFTR folding and trafficking to the apical plasma membrane (correctors for Class II mutations); and an increase in the function of CFTR channel (potentiators therapy for Class III mutations and any mutant with a residual function located at the membrane). Other therapies that are in preclinical development are not mutation specific and include gene therapy to edit the genome and stem cell therapy to repair the airway tissue. These strategies that are directed at the basic CF defects are now revolutionizing the treatment for patients and should positively impact their survival rates.
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Affiliation(s)
- Iwona Pranke
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Descartes, Paris, France
| | - Anita Golec
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Descartes, Paris, France
| | - Alexandre Hinzpeter
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Descartes, Paris, France
| | - Aleksander Edelman
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Descartes, Paris, France
| | - Isabelle Sermet-Gaudelus
- INSERM U 1151, Institut Necker Enfants Malades, Université Paris Descartes, Paris, France.,Centre de Référence Maladie Rare, Mucoviscidose et Maladies de CFTR, Paris, France.,Faculté de Médecine, Université Paris Descartes, Paris, France
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11
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Zhang J, Wang Y, Jiang X, Chan HC. Cystic fibrosis transmembrane conductance regulator-emerging regulator of cancer. Cell Mol Life Sci 2018; 75:1737-1756. [PMID: 29411041 PMCID: PMC11105598 DOI: 10.1007/s00018-018-2755-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 12/27/2017] [Accepted: 01/17/2018] [Indexed: 12/11/2022]
Abstract
Mutations of cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis, the most common life-limiting recessive genetic disease among Caucasians. CFTR mutations have also been linked to increased risk of various cancers but remained controversial for a long time. Recent studies have begun to reveal that CFTR is not merely an ion channel but also an important regulator of cancer development and progression with multiple signaling pathways identified. In this review, we will first present clinical findings showing the correlation of genetic mutations or aberrant expression of CFTR with cancer incidence in multiple cancers. We will then focus on the roles of CFTR in fundamental cellular processes including transformation, survival, proliferation, migration, invasion and epithelial-mesenchymal transition in cancer cells, highlighting the signaling pathways involved. Finally, the association of CFTR expression levels with patient prognosis, and the potential of CFTR as a cancer prognosis indicator in human malignancies will be discussed.
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Affiliation(s)
- Jieting Zhang
- Faculty of Medicine, Epithelial Cell Biology Research Center, School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, People's Republic of China
- Key Laboratory for Regenerative Medicine of the Ministry of Education of China, Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, People's Republic of China
- School of Biomedical Sciences Core Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China
| | - Yan Wang
- Faculty of Medicine, Epithelial Cell Biology Research Center, School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, People's Republic of China
- Key Laboratory for Regenerative Medicine of the Ministry of Education of China, Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, People's Republic of China
- School of Biomedical Sciences Core Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China
| | - Xiaohua Jiang
- Faculty of Medicine, Epithelial Cell Biology Research Center, School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, People's Republic of China.
- Key Laboratory for Regenerative Medicine of the Ministry of Education of China, Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, People's Republic of China.
- School of Biomedical Sciences Core Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China.
| | - Hsiao Chang Chan
- Faculty of Medicine, Epithelial Cell Biology Research Center, School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, People's Republic of China.
- Key Laboratory for Regenerative Medicine of the Ministry of Education of China, Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, People's Republic of China.
- School of Biomedical Sciences Core Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China.
- Sichuan University-The Chinese University of Hong Kong Joint Laboratory for Reproductive Medicine, West China Second University Hospital, Chengdu, People's Republic of China.
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12
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Villate-Beitia I, Zarate J, Puras G, Pedraz JL. Gene delivery to the lungs: pulmonary gene therapy for cystic fibrosis. Drug Dev Ind Pharm 2017; 43:1071-1081. [PMID: 28270008 DOI: 10.1080/03639045.2017.1298122] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cystic fibrosis (CF) is a monogenic autosomal recessive disorder where the defective gene, the cystic fibrosis transmembrane conductance regulator (CFTR), is well identified. Moreover, the respiratory tract can be targeted through noninvasive aerosolized formulations for inhalation. Therefore, gene therapy is considered a plausible strategy to address this disease. Conventional gene therapy strategies rely on the addition of a correct copy of the CFTR gene into affected cells in order to restore the channel activity. In recent years, genome correction strategies have emerged, such as zinc-finger nucleases, transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats associated to Cas9 nucleases. These gene editing tools aim to repair the mutated gene at its original genomic locus with high specificity. Besides, the success of gene therapy critically depends on the nucleic acids carriers. To date, several clinical studies have been carried out to add corrected copies of the CFTR gene into target cells using viral and non-viral vectors, some of them with encouraging results. Regarding genome editing systems, preliminary in vitro studies have been performed in order to repair the CFTR gene. In this review, after briefly introducing the basis of CF, we discuss the up-to-date gene therapy strategies to address the disease. The review focuses on the main factors to take into consideration when developing gene delivery strategies, such as the design of vectors and plasmid DNA, in vitro/in vivo tests, translation to human use, administration methods, manufacturing conditions and regulatory issues.
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Affiliation(s)
- Ilia Villate-Beitia
- a NanoBioCel Group, University of the Basque Country (UPV/EHU) , Vitoria-Gasteiz , Spain.,b Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) , Vitoria-Gasteiz , Spain
| | - Jon Zarate
- a NanoBioCel Group, University of the Basque Country (UPV/EHU) , Vitoria-Gasteiz , Spain.,b Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) , Vitoria-Gasteiz , Spain
| | - Gustavo Puras
- a NanoBioCel Group, University of the Basque Country (UPV/EHU) , Vitoria-Gasteiz , Spain.,b Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) , Vitoria-Gasteiz , Spain
| | - José Luis Pedraz
- a NanoBioCel Group, University of the Basque Country (UPV/EHU) , Vitoria-Gasteiz , Spain.,b Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) , Vitoria-Gasteiz , Spain
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13
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Mutyam V, Du M, Xue X, Keeling KM, White EL, Bostwick JR, Rasmussen L, Liu B, Mazur M, Hong JS, Falk Libby E, Liang F, Shang H, Mense M, Suto MJ, Bedwell DM, Rowe SM. Discovery of Clinically Approved Agents That Promote Suppression of Cystic Fibrosis Transmembrane Conductance Regulator Nonsense Mutations. Am J Respir Crit Care Med 2016; 194:1092-1103. [PMID: 27104944 PMCID: PMC5114449 DOI: 10.1164/rccm.201601-0154oc] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 04/21/2016] [Indexed: 01/03/2023] Open
Abstract
RATIONALE Premature termination codons (PTCs) in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF). Several agents are known to suppress PTCs but are poorly efficacious or toxic. OBJECTIVES To determine whether there are clinically available agents that elicit translational readthrough and improve CFTR function sufficient to confer therapeutic benefit to patients with CF with PTCs. METHODS Two independent screens, firefly luciferase and CFTR-mediated transepithelial chloride conductance assay, were performed on a library of 1,600 clinically approved compounds using fisher rat thyroid cells stably transfected with stop codons. Select agents were further evaluated using secondary screening assays including short circuit current analysis on primary cells from patients with CF. In addition, the effect of CFTR modulators (ivacaftor) was tested in combination with the most efficacious agents. MEASUREMENTS AND MAIN RESULTS From the primary screen, 48 agents were selected as potentially active. Following confirmatory tests in the transepithelial chloride conductance assay and prioritizing agents based on favorable pharmacologic properties, eight agents were advanced for secondary screening. Ivacaftor significantly increased short circuit current following forskolin stimulation in cells treated with pyranoradine tetraphosphate, potassium p-aminobenzoate, and escin as compared with vehicle control. Escin, an herbal agent, consistently induced readthrough activity as demonstrated by enhanced CFTR expression and function in vitro. CONCLUSIONS Clinically approved drugs identified as potential readthrough agents, in combination with ivacaftor, may induce nonsense suppression to restore therapeutic levels of CFTR function. One or more agents may be suitable to advance to human testing.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Marina Mazur
- Gregory Fleming James Cystic Fibrosis Research Center
| | - Jeong S. Hong
- Gregory Fleming James Cystic Fibrosis Research Center
- Department of Cell Developmental and Integrative Biology, and
| | | | - Feng Liang
- Cystic Fibrosis Foundation Therapeutics, Boston, Massachusetts
| | - Haibo Shang
- Cystic Fibrosis Foundation Therapeutics, Boston, Massachusetts
| | - Martin Mense
- Cystic Fibrosis Foundation Therapeutics, Boston, Massachusetts
| | | | - David M. Bedwell
- Department of Microbiology
- Gregory Fleming James Cystic Fibrosis Research Center
| | - Steven M. Rowe
- Department of Medicine
- Gregory Fleming James Cystic Fibrosis Research Center
- Department of Cell Developmental and Integrative Biology, and
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
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14
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Li J, Hao C, Ren L, Xiao Y, Wang J, Qin X. Data Mining of Lung Microbiota in Cystic Fibrosis Patients. PLoS One 2016; 11:e0164510. [PMID: 27741283 PMCID: PMC5065158 DOI: 10.1371/journal.pone.0164510] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/26/2016] [Indexed: 12/18/2022] Open
Abstract
The major therapeutic strategy used to treat exacerbated cystic fibrosis (CF) is antibiotic treatment. As this approach easily generates antibiotic-resistant strains of opportunistic bacteria, optimized antibiotic therapies are required to effectively control chronic and recurrent bacterial infections in CF patients. A promising future for the proper use of antibiotics is the management of lung microbiota. However, the impact of antibiotic treatments on CF microbiota and vice versa is not fully understood. This study analyzed 718 sputum samples from 18 previous studies to identify differences between CF and uninfected lung microbiota and to evaluate the effects of antibiotic treatments on exacerbated CF microbiota. A reference-based OTU (operational taxonomic unit) picking method was used to combine analyses of data generated using different protocols and platforms. Findings show that CF microbiota had greater richness and lower diversity in the community structure than uninfected control (NIC) microbiota. Specifically, CF microbiota showed higher levels of opportunistic bacteria and dramatically lower levels of commensal bacteria. Antibiotic treatment affected exacerbated CF microbiota notably but only transiently during the treatment period. Limited decrease of the dominant opportunistic bacteria and a dramatic decrease of commensal bacteria were observed during the antibiotic treatment for CF exacerbation. Simultaneously, low abundance opportunistic bacteria were thriving after the antibiotic treatment. The inefficiency of the current antibiotic treatment against major opportunistic bacteria and the detrimental effects on commensal bacteria indicate that the current empiric antibiotic treatment on CF exacerbation should be reevaluated and optimized.
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Affiliation(s)
- Jianguo Li
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan 030006, China
| | - Chunyan Hao
- College of Chemical & Biological Engineering, Taiyuan University of Science & Technology, Taiyuan 030021, China
| | - Lili Ren
- MOH Key Laboratory of System Pathogen Biology and Christophe Mérieux Laboratory, IPB, CAMS-Foundation Mérieux, Institute of Pathogen Biology (IPB), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - Yan Xiao
- MOH Key Laboratory of System Pathogen Biology and Christophe Mérieux Laboratory, IPB, CAMS-Foundation Mérieux, Institute of Pathogen Biology (IPB), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - Jianwei Wang
- MOH Key Laboratory of System Pathogen Biology and Christophe Mérieux Laboratory, IPB, CAMS-Foundation Mérieux, Institute of Pathogen Biology (IPB), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - Xuemei Qin
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan 030006, China
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15
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Birket SE, Chu KK, Houser GH, Liu L, Fernandez CM, Solomon GM, Lin V, Shastry S, Mazur M, Sloane PA, Hanes J, Grizzle WE, Sorscher EJ, Tearney GJ, Rowe SM. Combination therapy with cystic fibrosis transmembrane conductance regulator modulators augment the airway functional microanatomy. Am J Physiol Lung Cell Mol Physiol 2016; 310:L928-39. [PMID: 26968770 DOI: 10.1152/ajplung.00395.2015] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 03/08/2016] [Indexed: 11/22/2022] Open
Abstract
Recently approved therapies that modulate CFTR function have shown significant clinical benefit, but recent investigations regarding their molecular mechanism when used in combination have not been consistent with clinical results. We employed micro-optical coherence tomography as a novel means to assess the mechanism of action of CFTR modulators, focusing on the effects on mucociliary clearance. Primary human airway monolayers from patients with a G551D mutation responded to ivacaftor treatment with increased ion transport, airway surface liquid depth, ciliary beat frequency, and mucociliary transport rate, in addition to decreased effective viscosity of the mucus layer, a unique mechanism established by our findings. These endpoints are consistent with the benefit observed in G551D patients treated with ivacaftor, and identify a novel mechanism involving mucus viscosity. In monolayers derived from F508del patients, the situation is more complicated, compounded by disparate effects on CFTR expression and function. However, by combining ion transport measurements with functional imaging, we establish a crucial link between in vitro data and clinical benefit, a finding not explained by ion transport studies alone. We establish that F508del cells exhibit increased mucociliary transport and decreased mucus effective viscosity, but only when ivacaftor is added to the regimen. We further show that improvement in the functional microanatomy in vitro corresponds with lung function benefit observed in the clinical trials, whereas ion transport in vitro corresponds to changes in sweat chloride. Functional imaging reveals insights into clinical efficacy and CFTR biology that significantly impact our understanding of novel therapies.
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Affiliation(s)
- Susan E Birket
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kengyeh K Chu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts; Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts; Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts; and
| | - Grace H Houser
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Linbo Liu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts; Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts
| | - Courtney M Fernandez
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - George M Solomon
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Vivian Lin
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Suresh Shastry
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Marina Mazur
- Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama
| | - Peter A Sloane
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Justin Hanes
- Center for Nanomedicine, Department of Ophthalmology, and Department of Neurosurgery, Johns Hopkins Hospital, Baltimore, Maryland
| | - William E Grizzle
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Eric J Sorscher
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama
| | - Guillermo J Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts; Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts; Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts; and
| | - Steven M Rowe
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama; Department of Cellular, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama;
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16
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Solomon GM, Marshall SG, Ramsey BW, Rowe SM. Breakthrough therapies: Cystic fibrosis (CF) potentiators and correctors. Pediatr Pulmonol 2015; 50 Suppl 40:S3-S13. [PMID: 26097168 PMCID: PMC4620567 DOI: 10.1002/ppul.23240] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/29/2015] [Accepted: 06/03/2015] [Indexed: 12/28/2022]
Abstract
Cystic Fibrosis is caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene resulting in abnormal protein function. Recent advances of targeted molecular therapies and high throughput screening have resulted in multiple drug therapies that target many important mutations in the CFTR protein. In this review, we provide the latest results and current progress of CFTR modulators for the treatment of cystic fibrosis, focusing on potentiators of CFTR channel gating and Phe508del processing correctors for the Phe508del CFTR mutation. Special emphasis is placed on the molecular basis underlying these new therapies and emerging results from the latest clinical trials. The future directions for augmenting the rescue of Phe508del with CFTR modulators are also emphasized.
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Affiliation(s)
- George M Solomon
- Department of Medicine and the Gregory Fleming James Cystic Fibrosis Research Center, Birmingham, Alabama
| | - Susan G Marshall
- Division of Pulmonary Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington
| | - Bonnie W Ramsey
- Division of Pulmonary Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington.,Center for Clinical and Translational Research, Seattle Children's Research Institute, Seattle, Washington
| | - Steven M Rowe
- Department of Medicine and the Gregory Fleming James Cystic Fibrosis Research Center, Birmingham, Alabama.,Departments of Medicine, Pediatrics, Cell Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
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17
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Ruwald MH, Xu Parks X, Moss AJ, Zareba W, Baman J, McNitt S, Kanters JK, Shimizu W, Wilde AA, Jons C, Lopes CM. Stop-codon and C-terminal nonsense mutations are associated with a lower risk of cardiac events in patients with long QT syndrome type 1. Heart Rhythm 2015; 13:122-31. [PMID: 26318259 DOI: 10.1016/j.hrthm.2015.08.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND In long QT syndrome type 1 (LQT1), the location and type of mutations have been shown to affect the clinical outcome. Although haploinsufficiency, including stop-codon and frameshift mutations, has been associated with a lower risk of cardiac events in patients with LQT1, nonsense mutations have been presumed functionally equivalent. OBJECTIVE The purpose of this study was to evaluate clinical differences between patients with nonsense mutations. METHODS The study sample comprised 1090 patients with genetically confirmed mutations. Patients were categorized into 5 groups, depending on mutation type and location: missense not located in the high-risk cytoplasmic loop (c-loop) (n = 698), which is used as reference; missense c-loop (n = 192); stop-codon (n = 67); frameshift (n = 39); and others (n = 94). The primary outcome was a composite end point of syncope, aborted cardiac arrest, and long QT syndrome-related death (cardiac events). Outcomes were evaluated using the multivariate Cox proportional hazards regression analysis. Standard patch clamp techniques were used. RESULTS Compared to patients with missense non-c-loop mutations, the risk of cardiac events was reduced significantly in patients with stop-codon mutations (hazard ratio [HR] 0.57; 95% confidence interval [CI] 0.34-0.96; P = .035), but not in patients with frameshift mutations (HR 1.01; 95% CI 0.58-1.77; P = .97). Our data suggest that currents of the most common stop-codon mutant channel (Q530X) were larger than those of haploinsufficient channels (wild type: 42 ± 6 pA/pF, n = 20; Q530X+wild type: 79 ± 14 pA/pF, n = 20; P < .05) and voltage dependence of activation was altered. CONCLUSION Stop-codon mutations are associated with a lower risk of cardiac events in patients with LQT1, while frameshift mutations are associated with the same risk as the majority of the missense mutations. Our data indicate functional differences between these previously considered equivalent mutation subtypes.
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Affiliation(s)
- Martin H Ruwald
- Heart Research Follow-up Program, Division of Cardiology, University of Rochester Medical Center, Rochester, New York; Department of Cardiology, Gentofte Hospital, Hellerup, Denmark
| | - Xiaorong Xu Parks
- Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York
| | - Arthur J Moss
- Heart Research Follow-up Program, Division of Cardiology, University of Rochester Medical Center, Rochester, New York
| | - Wojciech Zareba
- Heart Research Follow-up Program, Division of Cardiology, University of Rochester Medical Center, Rochester, New York
| | - Jayson Baman
- Heart Research Follow-up Program, Division of Cardiology, University of Rochester Medical Center, Rochester, New York
| | - Scott McNitt
- Heart Research Follow-up Program, Division of Cardiology, University of Rochester Medical Center, Rochester, New York
| | - Jorgen K Kanters
- Department of Cardiology, Gentofte Hospital, Hellerup, Denmark; Laboratory of Experimental Cardiology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - Arthur A Wilde
- AMC Heart Centre, Department of Clinical and Experimental Cardiology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Christian Jons
- Department of Cardiology, Gentofte Hospital, Hellerup, Denmark
| | - Coeli M Lopes
- Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York.
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18
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Cholon DM, Quinney NL, Fulcher ML, Esther CR, Das J, Dokholyan NV, Randell SH, Boucher RC, Gentzsch M. Potentiator ivacaftor abrogates pharmacological correction of ΔF508 CFTR in cystic fibrosis. Sci Transl Med 2015; 6:246ra96. [PMID: 25101886 DOI: 10.1126/scitranslmed.3008680] [Citation(s) in RCA: 256] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR). Newly developed "correctors" such as lumacaftor (VX-809) that improve CFTR maturation and trafficking and "potentiators" such as ivacaftor (VX-770) that enhance channel activity may provide important advances in CF therapy. Although VX-770 has demonstrated substantial clinical efficacy in the small subset of patients with a mutation (G551D) that affects only channel activity, a single compound is not sufficient to treat patients with the more common CFTR mutation, ΔF508. Thus, patients with ΔF508 will likely require treatment with both correctors and potentiators to achieve clinical benefit. However, whereas the effectiveness of acute treatment with this drug combination has been demonstrated in vitro, the impact of chronic therapy has not been established. In studies of human primary airway epithelial cells, we found that both acute and chronic treatment with VX-770 improved CFTR function in cells with the G551D mutation, consistent with clinical studies. In contrast, chronic VX-770 administration caused a dose-dependent reversal of VX-809-mediated CFTR correction in ΔF508 homozygous cultures. This result reflected the destabilization of corrected ΔF508 CFTR by VX-770, markedly increasing its turnover rate. Chronic VX-770 treatment also reduced mature wild-type CFTR levels and function. These findings demonstrate that chronic treatment with CFTR potentiators and correctors may have unexpected effects that cannot be predicted from short-term studies. Combining these drugs to maximize rescue of ΔF508 CFTR may require changes in dosing and/or development of new potentiator compounds that do not interfere with CFTR stability.
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Affiliation(s)
- Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nancy L Quinney
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - M Leslie Fulcher
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Charles R Esther
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Division of Pediatric Pulmonology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jhuma Das
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nikolay V Dokholyan
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Scott H Randell
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Richard C Boucher
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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19
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Boyle MP, Bell SC, Konstan MW, McColley SA, Rowe SM, Rietschel E, Huang X, Waltz D, Patel NR, Rodman D. A CFTR corrector (lumacaftor) and a CFTR potentiator (ivacaftor) for treatment of patients with cystic fibrosis who have a phe508del CFTR mutation: a phase 2 randomised controlled trial. THE LANCET. RESPIRATORY MEDICINE 2014; 2:527-38. [PMID: 24973281 DOI: 10.1016/s2213-2600(14)70132-8] [Citation(s) in RCA: 328] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The phe508del CFTR mutation causes cystic fibrosis by limiting the amount of CFTR protein that reaches the epithelial cell surface. We tested combination treatment with lumacaftor, an investigational CFTR corrector that increases trafficking of phe508del CFTR to the cell surface, and ivacaftor, a CFTR potentiator that enhances chloride transport of CFTR on the cell surface. METHODS In this phase 2 clinical trial, we assessed three successive cohorts, with the results of each cohort informing dose selection for the subsequent cohort. We recruited patients from 24 cystic fibrosis centres in Australia, Belgium, Germany, New Zealand, and the USA. Eligibility criteria were: confirmed diagnosis of cystic fibrosis, age at least 18 years, and a forced expiratory volume in 1 s (FEV1) of 40% or more than predicted. Cohort 1 included phe508del CFTR homozygous patients randomly assigned to either lumacaftor 200 mg once per day for 14 days followed by addition of ivacaftor 150 mg or 250 mg every 12 h for 7 days, or 21 days of placebo. Together, cohorts 2 and 3 included phe508del CFTR homozygous and heterozygous patients, randomly assigned to either 56 days of lumacaftor (cohort 2: 200 mg, 400 mg, or 600 mg once per day, cohort 3: 400 mg every 12 h) with ivacaftor 250 mg every 12 h added after 28 days, or 56 days of placebo. The primary outcomes for all cohorts were change in sweat chloride concentration during the combination treatment period in the intention-to-treat population and safety (laboratory measurements and adverse events). The study is registered with ClinicalTrials.gov, number NCT01225211, and EudraCT, number 2010-020413-90. FINDINGS Cohort 1 included 64 participants. Cohort 2 and 3 combined contained 96 phe508del CFTR homozygous patients and 28 compound heterozygotes. Treatment with lumacaftor 200 mg once daily and ivacaftor 250 mg every 12 h decreased mean sweat chloride concentration by 9.1 mmol/L (p<0.001) during the combination treatment period in cohort 1. In cohorts 2 and 3, mean sweat chloride concentration did not decrease significantly during combination treatment in any group. Frequency and nature of adverse events were much the same in the treatment and placebo groups during the combination treatment period; the most commonly reported events were respiratory. 12 of 97 participants had chest tightness or dyspnoea during treatment with lumacaftor alone. In pre-planned secondary analyses, a significant decrease in sweat chloride concentration occurred in the treatment groups between day 1 and day 56 (lumacaftor 400 mg once per day group -9.1 mmol/L, p<0.001; lumacaftor 600 mg once per day group -8.9 mmol/L, p<0.001; lumacaftor 400 mg every 12 h group -10.3 mmol/L, p=0.002). These changes were significantly greater than the change in the placebo group. In cohort 2, the lumacaftor 600 mg once per day significantly improved FEV1 from day 1 to 56 (difference compared with placebo group: +5.6 percentage points, p=0.013), primarily during the combination period. In cohort 3, FEV1 did not change significantly across the entire study period compared with placebo (difference +4.2 percentage points, p=0.132), but did during the combination period (difference +7.7 percentage points, p=0·003). Phe508del CFTR heterozygous patients did not have a significant improvement in FEV1. INTERPRETATION We provide evidence that combination lumacaftor and ivacaftor improves FEV1 for patients with cystic fibrosis who are homozygous for phe508del CFTR, with a modest effect on sweat chloride concentration. These results support the further exploration of combination lumacaftor and ivacaftor as a treatment in this setting. FUNDING Vertex Pharmaceuticals, Cystic Fibrosis Foundation Therapeutics Development Network.
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Affiliation(s)
| | - Scott C Bell
- The Prince Charles Hospital, Brisbane, QLD, Australia
| | - Michael W Konstan
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | | | - Steven M Rowe
- University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ernst Rietschel
- Children's Hospital, University of Cologne, Cologne, Germany
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Jennings MT, Riekert KA, Boyle MP. Update on key emerging challenges in cystic fibrosis. Med Princ Pract 2014; 23:393-402. [PMID: 24434297 PMCID: PMC5586905 DOI: 10.1159/000357646] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 12/01/2013] [Indexed: 12/29/2022] Open
Abstract
Cystic fibrosis (CF) is a multisystem disease causing severe chronic sinopulmonary disease and loss of pancreatic exocrine function, which affects approximately 70,000 individuals worldwide. New therapeutic developments over the last few decades have resulted in a significant increase in survival, with the median predicted survival now reaching the late thirties and more and more CF patients living well into adulthood. However, with this advent of new therapies and the associated increase in survival, new challenges in CF care have also emerged. Two of these challenges, i.e. chronic methicillin-resistant Staphylococcus aureus lung infection and patient adherence to very complicated and time-consuming therapeutic regimens, are reviewed in detail here. In addition, the ultimate challenge of treating the underlying cause of CF by correcting the dysfunction of the CF transmembrane conductance regulator chloride channel is reviewed, as agents to correct channel function will likely significantly alter CF clinical outcomes and treatment approaches in the next decade.
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Affiliation(s)
| | | | - Michael P. Boyle
- *Michael P. Boyle, MD, 1830 E. Monument Street, 5th floor, Baltimore, MD 21205 (USA), E-Mail
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21
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Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Catterall WA, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: ion channels. Br J Pharmacol 2013; 170:1607-51. [PMID: 24528239 PMCID: PMC3892289 DOI: 10.1111/bph.12447] [Citation(s) in RCA: 224] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. Ion channels are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
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Affiliation(s)
- Stephen PH Alexander
- School of Life Sciences, University of Nottingham Medical SchoolNottingham, NG7 2UH, UK
- *
Author for correspondence;
| | - Helen E Benson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Elena Faccenda
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Adam J Pawson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Joanna L Sharman
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - William A Catterall
- University of Washington, School of Medicine, Department of PharmacologyBox 357280, Seattle, WA 98195-7280, USA
| | | | - John A Peters
- Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of DundeeDundee, DD1 9SY, UK
| | - Anthony J Harmar
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
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Rowe SM, Verkman AS. Cystic fibrosis transmembrane regulator correctors and potentiators. Cold Spring Harb Perspect Med 2013; 3:3/7/a009761. [PMID: 23818513 DOI: 10.1101/cshperspect.a009761] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cystic fibrosis (CF) is caused by loss-of-function mutations in the CF transmembrane conductance regulator (CFTR) protein, a cAMP-regulated anion channel expressed primarily at the apical plasma membrane of secretory epithelia. Nearly 2000 mutations in the CFTR gene have been identified that cause disease by impairing its translation, cellular processing, and/or chloride channel gating. The fundamental premise of CFTR corrector and potentiator therapy for CF is that addressing the underlying defects in the cellular processing and chloride channel function of CF-causing mutant CFTR alleles will result in clinical benefit by addressing the basic defect underlying CF. Correctors are principally targeted at F508del cellular misprocessing, whereas potentiators are intended to restore cAMP-dependent chloride channel activity to mutant CFTRs at the cell surface. This article reviews the discovery of CFTR potentiators and correctors, what is known regarding their mechanistic basis, and encouraging results achieved in clinical testing.
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Affiliation(s)
- Steven M Rowe
- Department of Medicine, Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Alabama 35294, USA
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Condren ME, Bradshaw MD. Ivacaftor: a novel gene-based therapeutic approach for cystic fibrosis. J Pediatr Pharmacol Ther 2013; 18:8-13. [PMID: 23616732 DOI: 10.5863/1551-6776-18.1.8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Ivacaftor is a new therapeutic agent that acts at the cystic fibrosis transmembrane conductance regulator (CFTR) channel to alter activity. It is approved for use in patients 6 years and older with cystic fibrosis who have at least 1 G551D mutation in the CFTR gene. It is unlike any other current pharmacologic agent for cystic fibrosis in that it specifically targets the gene defect associated with cystic fibrosis as opposed to treating resulting symptomology. Mucoactive agents, antibiotics, inhaled beta agonists, and other anti-inflammatory agents are currently the mainstay of cystic fibrosis treatment but can be associated with several side effects in addition to cumbersome frequency of administration. Ivacaftor's oral dosing regimen offers a more convenient treatment option. However, it is associated with significant drug-drug interactions.
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Affiliation(s)
- Michelle E Condren
- Department of Pharmacy Clinical and Administrative Sciences-Tulsa, University of Oklahoma College of Pharmacy, Tulsa, Oklahoma ; Department of Pediatrics, University of Oklahoma School of Community Medicine, Tulsa, Oklahoma
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Cohen-Cymberknoh M, Yaakov Y, Shoseyov D, Shteyer E, Schachar E, Rivlin J, Bentur L, Picard E, Aviram M, Israeli E, Kerem E, Wilschanski M. Evaluation of the intestinal current measurement method as a diagnostic test for cystic fibrosis. Pediatr Pulmonol 2013; 48:229-35. [PMID: 22553157 DOI: 10.1002/ppul.22586] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Accepted: 03/20/2012] [Indexed: 01/09/2023]
Abstract
BACKGROUND The sweat test and nasal potential difference measurement are now established tools in the diagnostic work up of cystic fibrosis (CF). Intestinal current measurement (ICM) is under consideration as an aid in the diagnosis of CF especially in young children. The aim of this study is to evaluate the diagnostic reliability of ICM. METHODS Rectal biopsies were obtained from three groups: CF patients, controls, and patients who were suspected for CF. ICMs were performed by mounting the rectal biopsy in an Ussing chamber and sequentially adding secretagogues while recording current changes. RESULTS Twenty-one CF patients (aged 3.0 ± 3.8 years) and 16 controls (aged 15.6 ± 15.1 years) were examined and have remarkably different results (presented as µA/cm(2) ): carbachol 16.3 ± 6.9, histamine 13.2 ± 8.9, and cAMP/forskolin 4.8 ± 4.0 for control group and carbachol -1.5 ± 5.3 (P < 0.0001), histamine -1.5 ± 3.1 (P < 0.0001), and cAMP/forskolin 0.36 ± 0.67 (P < 0.0001) for the CF group. Our suggested reference values are: +5.40, +3.52, +2.19 for carbachol, histamine, and cAMP/forskolin, respectively. The combination parameter (the arithmetic sum of carbachol, histamine, and cAMP/forskolin) of +7.19 differentiates normal from abnormal (ROC curve analysis, area under the curve = 1.00, both sensitivity and specificity are 100%). This statistical model was applied to 71 patients suspected for CF and revealed that 66 patients had normal ICM results (combination >7.19) and five patients had abnormal ICM results (combination <7.19). CONCLUSION We have shown that ICM tests may be useful to differentiate between patients suspected to have CF. These results require confirmation so that ICM may be included in diagnostic algorithms.
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Affiliation(s)
- Malena Cohen-Cymberknoh
- CF Center and Department of Pediatrics, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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Moniz S, Sousa M, Moraes BJ, Mendes AI, Palma M, Barreto C, Fragata JI, Amaral MD, Matos P. HGF stimulation of Rac1 signaling enhances pharmacological correction of the most prevalent cystic fibrosis mutant F508del-CFTR. ACS Chem Biol 2013; 8:432-42. [PMID: 23148778 DOI: 10.1021/cb300484r] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Cystic fibrosis (CF), a major life-limiting genetic disease leading to severe respiratory symptoms, is caused by mutations in CF transmembrane conductance regulator (CFTR), a chloride (Cl(-)) channel expressed at the apical membrane of epithelial cells. Absence of functional CFTR from the surface of respiratory cells reduces mucociliary clearance, promoting airways obstruction, chronic infection, and ultimately lung failure. The most frequent mutation, F508del, causes the channel to misfold, triggering its premature degradation and preventing it from reaching the cell surface. Recently, novel small-molecule correctors rescuing plasma membrane localization of F508del-CFTR underwent clinical trials but with limited success. Plausibly, this may be due to the mutant intrinsic plasma membrane (PM) instability. Herein, we show that restoration of F508del-CFTR PM localization by correctors can be dramatically improved through a novel pathway involving stimulation of signaling by the endogenous small GTPase Rac1 via hepatocyte growth factor (HGF). We first show that CFTR anchors to apical actin cytoskeleton (via Ezrin) upon activation of Rac1 signaling through PIP5K and Arp2/3. We then found that such anchoring retains pharmacologically rescued F508del-CFTR at the cell surface, boosting functional restoration by correctors up to 30% of wild-type channel levels in human airway epithelial cells. Our findings reveal that surface anchoring and retention is a major target pathway for CF pharmacotherapy, namely, to achieve maximal restoration of F508del-CFTR in patients in combination with correctors. Moreover, this approach may also translate to other disorders caused by trafficking-deficient surface proteins.
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Affiliation(s)
- Sónia Moniz
- Department of Genetics, National Health Institute ‘Dr. Ricardo Jorge’, Av. Padre Cruz, 1649-016 Lisboa;
Portugal
- Faculty of Sciences,
BioFIG
- Centre for Biodiversity, Functional and Integrative Genomics, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa,
Portugal
| | - Marisa Sousa
- Department of Genetics, National Health Institute ‘Dr. Ricardo Jorge’, Av. Padre Cruz, 1649-016 Lisboa;
Portugal
- Faculty of Sciences,
BioFIG
- Centre for Biodiversity, Functional and Integrative Genomics, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa,
Portugal
| | - Bruno José Moraes
- Department of Genetics, National Health Institute ‘Dr. Ricardo Jorge’, Av. Padre Cruz, 1649-016 Lisboa;
Portugal
- Faculty of Sciences,
BioFIG
- Centre for Biodiversity, Functional and Integrative Genomics, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa,
Portugal
| | - Ana Isabel Mendes
- Department of Genetics, National Health Institute ‘Dr. Ricardo Jorge’, Av. Padre Cruz, 1649-016 Lisboa;
Portugal
- Faculty of Sciences,
BioFIG
- Centre for Biodiversity, Functional and Integrative Genomics, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa,
Portugal
| | - Marta Palma
- Faculty of Sciences,
BioFIG
- Centre for Biodiversity, Functional and Integrative Genomics, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa,
Portugal
| | - Celeste Barreto
- Department of Pediatrics, Hospital de Santa Maria, Avenida Professor Egas Moniz,
1649-035 Lisboa, Portugal
| | - José I. Fragata
- Department of Cardiothoracic
Surgery, Hospital de Santa Marta, R. de
Santa Marta 50, 1169-024 Lisboa, Portugal
| | - Margarida D. Amaral
- Department of Genetics, National Health Institute ‘Dr. Ricardo Jorge’, Av. Padre Cruz, 1649-016 Lisboa;
Portugal
- Faculty of Sciences,
BioFIG
- Centre for Biodiversity, Functional and Integrative Genomics, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa,
Portugal
| | - Paulo Matos
- Department of Genetics, National Health Institute ‘Dr. Ricardo Jorge’, Av. Padre Cruz, 1649-016 Lisboa;
Portugal
- Faculty of Sciences,
BioFIG
- Centre for Biodiversity, Functional and Integrative Genomics, University of Lisboa, Campo Grande-C8, 1749-016 Lisboa,
Portugal
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A new era in the treatment of cystic fibrosis: correction of the underlying CFTR defect. THE LANCET RESPIRATORY MEDICINE 2013; 1:158-63. [PMID: 24429096 DOI: 10.1016/s2213-2600(12)70057-7] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cystic fibrosis is caused by dysfunction or deficiency of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, an epithelial chloride channel that has a key role in maintaining homoeostasis of the airway surface liquid layer in the lungs. More than 1900 CFTR mutations that might result in a disease phenotype have been identified; these can be grouped into classes on the basis of their effect on CFTR protein production, trafficking, function, and stability. In the past 2 years, landmark clinical trials have shown that correction of CFTR function leads to substantial clinical benefit for individuals with cystic fibrosis. These findings are ushering in a new era of cystic fibrosis treatments designed to correct the underlying CFTR defect caused by different mutation classes. With analysis of continuing trials and available patient registries, here we assess mutation types and the number and geographical distribution of patients who are likely to benefit from CFTR-correcting treatment.
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Villella VR, Esposito S, Bruscia EM, Maiuri MC, Raia V, Kroemer G, Maiuri L. Targeting the Intracellular Environment in Cystic Fibrosis: Restoring Autophagy as a Novel Strategy to Circumvent the CFTR Defect. Front Pharmacol 2013; 4:1. [PMID: 23346057 PMCID: PMC3549520 DOI: 10.3389/fphar.2013.00001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 01/01/2013] [Indexed: 12/18/2022] Open
Abstract
Cystic fibrosis (CF) patients harboring the most common deletion mutation of the CF transmembrane conductance regulator (CFTR), F508del, are poor responders to potentiators of CFTR channel activity which can be used to treat a small subset of CF patients who genetically carry plasma membrane (PM)-resident CFTR mutants. The misfolded F508del-CFTR protein is unstable in the PM even if rescued by pharmacological agents that prevent its intracellular retention and degradation. CF is a conformational disease in which defective CFTR induces an impressive derangement of general proteostasis resulting from disabled autophagy. In this review, we discuss how rescuing Beclin 1 (BECN1), a major player of autophagosome formation, either by means of direct gene transfer or indirectly by administration of proteostasis regulators, could stabilize F508del-CFTR at the PM. We focus on the relationship between the improvement of peripheral proteostasis and CFTR PM stability in F508del-CFTR homozygous bronchial epithelia or mouse lungs. Moreover, this article reviews recent pre-clinical evidence indicating that targeting the intracellular environment surrounding the misfolded mutant CFTR instead of protein itself could constitute an attractive therapeutic option to sensitize patients carrying the F508del-CFTR mutation to the beneficial action of CFTR potentiators on lung inflammation.
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Affiliation(s)
- Valeria Rachela Villella
- European Institute for Research in Cystic Fibrosis, San Raffaele Scientific Institute Milan, Italy
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Zystische Fibrose. PÄDIATRISCHE GASTROENTEROLOGIE, HEPATOLOGIE UND ERNÄHRUNG 2013. [PMCID: PMC7498778 DOI: 10.1007/978-3-642-24710-1_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Die zystische Fibrose (Synonym: Mukoviszidose) ist auch heute noch eine unheilbare, letal verlaufende Krankheit. Durch die fortlaufende Verbesserung der Therapie ist es in den vergangenen Jahren gelungen, Lebenserwartung und Lebensqualität deutlich zu verbessern. Im Rahmen der Multisystemerkrankung finden sich im Gastrointestinaltrakt wichtige Manifestationen (an Pankreas, Dünndarm, Leber und Gallenwegen), die mit der auch heute noch prognostisch ungünstigen, aber häufig vorkommenden Ernährungsstörung zusammengehen. Frühdiagnose und Frühtherapie können das Auftreten von Komplikationen verhindern bzw. hinauszögern. Neueste Daten zeigen, dass eine mutationsspezifische pharmakologische Therapie auf Ionenkanalebene wirksam ist. Die konventionelle, zentrumorientierte und qualitätsgesicherte Behandlung der zystischen Fibrose erfordert den integrierten Einsatz der pädiatrischen Gastroenterologie.
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Prota LFM, Cebotaru L, Cheng J, Wright J, Vij N, Morales MM, Guggino WB. Dexamethasone regulates CFTR expression in Calu-3 cells with the involvement of chaperones HSP70 and HSP90. PLoS One 2012; 7:e47405. [PMID: 23272037 PMCID: PMC3521767 DOI: 10.1371/journal.pone.0047405] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 09/12/2012] [Indexed: 12/03/2022] Open
Abstract
Background Dexamethasone is widely used for pulmonary exacerbation in patients with cystic fibrosis, however, not much is known about the effects of glucocorticoids on the wild-type cystic fibrosis channel transmembrane regulator (CFTR). Our aim was to determine the effects of dexamethasone treatment on wild-type CFTR expression. Methods and Results Dose–response (1 nM to 10 µM) and time course (3 to 48 h) curves were generated for dexamethasone for mRNA expression in Calu-3 cells using a real-time PCR. Within 24 h, dexamethasone (10 nM) showed a 0.3-fold decrease in CFTR mRNA expression, and a 3.2-fold increase in αENaC mRNA expression compared with control groups. Dexamethasone (10 nM) induced a 1.97-fold increase in the total protein of wild-type CFTR, confirmed by inhibition by mifepristone. To access surface protein expression, biotinylation followed by Western blotting showed that dexamethasone treatment led to a 2.35-fold increase in the amount of CFTR in the cell surface compared with the untreated control groups. Once protein translation was inhibited with cycloheximide, dexamethasone could not increase the amount of CFTR protein. Protein stability was assessed by inhibition of protein synthesis with cycloheximide (50 µg/ml) at different times in cells treated with dexamethasone and in untreated cells. Dexamethasone did not alter the degradation of wild-type CFTR. Assessment of the B band of CFTR within 15 min of metabolic pulse labeling showed a 1.5-fold increase in CFTR protein after treatment with dexamethasone for 24 h. Chaperone 90 (HSP90) binding to CFTR increased 1.55-fold after treatment with dexamethasone for 24 h, whereas chaperone 70 (HSP70) binding decreased 0.30 fold in an immunoprecipitation assay. Conclusion Mature wild-type CFTR protein is regulated by dexamethasone post transcription, involving cotranslational mechanisms with HSP90 and HSP70, which enhances maturation and expression of wild-type CFTR.
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Affiliation(s)
- Luiz Felipe M. Prota
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Laboratory of Cellular and Molecular Physiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Liudmila Cebotaru
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Jie Cheng
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Jerry Wright
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Neeraj Vij
- Department of Pediatrics and Institute of Nanobiotechnology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Marcelo M. Morales
- Laboratory of Cellular and Molecular Physiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
| | - William B. Guggino
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
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Leonard A, Leal T, Lebecque P. [Mucoviscidosis: CFTR mutation-specific therapy: a ray of sunshine in a cloudy sky]. Arch Pediatr 2012. [PMID: 23199563 DOI: 10.1016/j.arcped.2012.10.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
There is a need to find a cure for pulmonary disease in cystic fibrosis (CF), though full benefit of this approach will be restricted to those patients with well-preserved lungs. The most promising route is currently that of a pharmacological mutation-specific approach aiming at correcting the mechanism by which mutations lead to impairment of chloride conductance across respiratory epithelial cells. In the past 14years, 7 candidate drugs (CPX, 4PBA, gentamicin, PTC124, VX-770 or Ivacaftor, VX-809 or Lumacaftor, and Miglustat) have been investigated in CF patients. A postulate of 14 out of the 15 published studies has been that an effective agent had to improve total chloride secretion as assessed in vivo by nasal potential difference measurements. The present review casts a critical look at these studies. Apparent inconsistencies are discussed as well as possible limitations of nasal potential difference measurements as outcome parameters in these trials. Primarily targeting a mutation carried by less than 2% of French CF patients, the 2 Ivacaftor studies could well be a milestone on the long road toward a cure for CF. However, further data on safety and long-term efficacy are obviously needed and the current price of this medication in the US would make it unaffordable for European patients.
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Affiliation(s)
- A Leonard
- Unité de pneumologie pédiatrique et mucoviscidose, cliniques Saint-Luc, université de Louvain, Bruxelles, Belgique.
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Efficacy of liposomal bismuth-ethanedithiol-loaded tobramycin after intratracheal administration in rats with pulmonary Pseudomonas aeruginosa infection. Antimicrob Agents Chemother 2012; 57:569-78. [PMID: 23147741 DOI: 10.1128/aac.01634-12] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We sought to investigate alterations in quorum-sensing signal molecule N-acyl homoserine lactone secretion and in the release of Pseudomonas aeruginosa virulence factors, as well as the in vivo antimicrobial activity of bismuth-ethanedithiol incorporated into a liposome-loaded tobramycin formulation (LipoBiEDT-TOB) administered to rats chronically infected with P. aeruginosa. The quorum-sensing signal molecule N-acyl homoserine lactone was monitored by using a biosensor organism. P. aeruginosa virulence factors were assessed spectrophotometrically. An agar beads model of chronic Pseudomonas lung infection in rats was used to evaluate the efficacy of the liposomal formulation in the reduction of bacterial count. The levels of active tobramycin in the lungs and the kidneys were evaluated by microbiological assay. LipoBiEDT-TOB was effective in disrupting both quorum-sensing signal molecules N-3-oxo-dodeccanoylhomoserine lactone and N-butanoylhomoserine lactone, as well as significantly (P < 0.05) reducing lipase, chitinase, and protease production. At 24 h after 3 treatments, the CFU counts in lungs of animals treated with LipoBiEDT-TOB were of 3 log(10) CFU/lung, comparated to 7.4 and 4.7 log(10) CFU/lung, respectively, in untreated lungs and in lungs treated with free antibiotic. The antibiotic concentration after the last dose of LipoBiEDT-TOB was 25.1 μg/lung, while no tobramycin was detected in the kidneys. As for the free antibiotic, we found 6.5 μg/kidney but could not detect any tobramycin in the lungs. Taken together, LipoBiEDT-TOB reduced the production of quorum-sensing molecules and virulence factors and could highly improve the management of chronic pulmonary infection in cystic fibrosis patients.
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Mahley RW, Huang Y. Small-molecule structure correctors target abnormal protein structure and function: structure corrector rescue of apolipoprotein E4-associated neuropathology. J Med Chem 2012; 55:8997-9008. [PMID: 23013167 PMCID: PMC4904786 DOI: 10.1021/jm3008618] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
An attractive strategy to treat proteinopathies (diseases caused by malformed or misfolded proteins) is to restore protein function by inducing proper three-dimensional structure. We hypothesized that this approach would be effective in reversing the detrimental effects of apolipoprotein (apo) E4, the major allele that significantly increases the risk of developing Alzheimer's disease and other neurodegenerative disorders. ApoE4's detrimental effects result from its altered protein conformation ("domain interaction"), making it highly susceptible to proteolytic cleavage and the generation of neurotoxic fragments. Here, we review apoE structure and function and how apoE4 causes neurotoxicity, and describe the identification of potent small-molecule-based "structure correctors" that induce proper apoE4 folding. SAR studies identified a series of small molecules that significantly reduced apoE4's neurotoxic effects in cultured neurons and a series that reduced apoE4 fragment levels in vivo, providing proof-of-concept for our approach. Structure-corrector-based therapies could prove to be highly effective for the treatment of many protein-misfolding diseases.
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Affiliation(s)
- Robert W Mahley
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, California 94158, United States.
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Bordeira-Carriço R, Pêgo AP, Santos M, Oliveira C. Cancer syndromes and therapy by stop-codon readthrough. Trends Mol Med 2012; 18:667-78. [PMID: 23044248 DOI: 10.1016/j.molmed.2012.09.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Revised: 08/10/2012] [Accepted: 09/17/2012] [Indexed: 12/19/2022]
Abstract
Several hereditary cancer syndromes are associated with nonsense mutations that create premature termination codons (PTC). Therapeutic strategies involving readthrough induction partially restore expression of proteins with normal function from nonsense-mutated genes, and small molecules such as aminoglycosides and PTC124 have exhibited promising results for treating patients with cystic fibrosis and Duchenne muscular dystrophy. Transgenic expression of suppressor-tRNAs and depleting translation termination factors are, among others, potential strategies for treating PTC-associated diseases. In this review, the potential of using readthrough strategies as a therapy for cancer syndromes is discussed, and we consider the effect of nonsense-mediated decay and other factors on readthrough efficiency.
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Rowe SM, Borowitz DS, Burns JL, Clancy JP, Donaldson SH, Retsch-Bogart G, Sagel SD, Ramsey BW. Progress in cystic fibrosis and the CF Therapeutics Development Network. Thorax 2012; 67:882-90. [PMID: 22960984 PMCID: PMC3787701 DOI: 10.1136/thoraxjnl-2012-202550] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cystic fibrosis (CF), the most common life-shortening genetic disorder in Caucasians, affects approximately 70 000 individuals worldwide. In 1998, the Cystic Fibrosis Foundation (CFF) launched the CF Therapeutics Development Network (CF-TDN) as a central element of its Therapeutics Development Programme. Designed to accelerate the clinical evaluation of new therapies needed to fulfil the CFF mission to control and cure CF, the CF-TDN has conducted 75 clinical trials since its inception, and has contributed to studies as varied as initial safety and proof of concept trials to pivotal programmes required for regulatory approval. This review highlights recent and significant research efforts of the CF-TDN, including a summary of contributions to studies involving CF transmembrane conductance regulator (CFTR) modulators, airway surface liquid hydrators and mucus modifiers, anti-infectives, anti-inflammatories, and nutritional therapies. Efforts to advance CF biomarkers, necessary to accelerate the therapeutic goals of the network, are also summarised.
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Affiliation(s)
- Steven M Rowe
- Department of Medicine, University of Alabama at Birmingham, 1819 University Boulevard (MCLM 768), Birmingham, AL 35294, USA.
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Sawicki GS, Tiddens H. Managing treatment complexity in cystic fibrosis: challenges and opportunities. Pediatr Pulmonol 2012; 47:523-33. [PMID: 22467341 DOI: 10.1002/ppul.22546] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 02/15/2012] [Indexed: 12/30/2022]
Abstract
Cystic fibrosis (CF) is a complex, chronic, multisystem disease for which there is currently no cure. Nonetheless, advances in management have led to dramatic improvements in patient survival. With this development, new issues have arisen for CF patients and their care providers, including an increased symptom burden and increased frequency of co-morbidities as patients reach older ages, leading to the need for a highly complicated and time-consuming regimen of treatments. Such high symptom and treatment burden often leads to non-adherence and low levels of competence with administration of therapy, both of which may have detrimental impacts on CF outcomes. Optimal management is also hindered by other patient-related factors, including inadequacies in disease education which may lead to issues with self-management. This is particularly important during the transition from parent-directed therapy to independent self-management that occurs during adolescence and early adulthood. Clinicians are also faced with a considerable challenge when selecting interventions for individual patients; although the paradigm of aggressive care necessitates a wide range of therapies, there is a limited evidence base with which to compare available therapeutic regimens. Novel pharmacological agents are being developed to target the underlying cause of CF, while non-pharmacological interventions aim to improve competence and maximize adherence and health outcomes. Comparative effectiveness research is needed to simplify management and facilitate the implementation of appropriate treatment strategies.
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Affiliation(s)
- Gregory S Sawicki
- Division of Respiratory Diseases, Children's Hospital Boston, Boston, Massachusetts 02115, USA.
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Readthrough of long-QT syndrome type 1 nonsense mutations rescues function but alters the biophysical properties of the channel. Biochem J 2012; 443:635-42. [DOI: 10.1042/bj20111912] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The nonsense mutations R518X-KCNQ1 and Q530X-KCNQ1 cause LQT1 (long-QT syndrome type 1) and result in a complete loss of IKs channel function. In the present study we attempted to rescue the function of these mutants, in HEK (human embryonic kidney)-293 cells, by promoting readthrough of their PTCs (premature termination codons) using the pharmacological agents G-418, gentamicin and PTC124. Gentamicin and G-418 acted to promote full-length channel protein expression from R518X at 100 μM and from Q530X at 1 mM. In contrast, PTC124 did not, at any dose tested, induce readthrough of either mutant. G-418 (1 mM) treatment also acted to significantly (P<0.05) increase current density and peak-tail current density, at +80 mV for R518X, but not Q530X, to 58±11% and 82±17% of the wild-type level respectively. However, the biophysical properties of the currents produced from R518X, while similar, were not identical with wild-type as the voltage-dependence of activation was significantly (P<0.05) shifted by +25 mV. Overall, these findings indicate that although functional rescue of LQT1 nonsense mutations is possible, it is dependent on the degree of readthrough achieved and the effect on channel function of the amino acid substituted for the PTC. Such considerations will determine the success of future therapies.
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Nayak RP. Latest in cystic fibrosis. MISSOURI MEDICINE 2012; 109:127-132. [PMID: 22675793 PMCID: PMC6181745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Cystic Fibrosis (CF) is a genetic disease affecting multiple organs. There are about 30,000 patients with CF in the United States, resulting from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, as well as its protein product. The life expectancy of CF patients has increased steadily over recent years, with the current expectation being for them to live into their late 30s. This is due to increased understanding, and therapeutic advances in the CF treatment armamentarium.
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Affiliation(s)
- Ravi P Nayak
- Division of Pulmonary, Critical Care, and Sleep Medicine, Saint Louis University School of Medicine, USA.
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Monterisi S, Favia M, Guerra L, Cardone RA, Marzulli D, Reshkin SJ, Casavola V, Zaccolo M. CFTR regulation in human airway epithelial cells requires integrity of the actin cytoskeleton and compartmentalized cAMP and PKA activity. J Cell Sci 2012; 125:1106-17. [PMID: 22302988 DOI: 10.1242/jcs.089086] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) mutation ΔF508CFTR still causes regulatory defects when rescued to the apical membrane, suggesting that the intracellular milieu might affect its ability to respond to cAMP regulation. We recently reported that overexpression of the Na(+)/H(+) exchanger regulatory factor NHERF1 in the cystic fibrosis (CF) airway cell line CFBE41o-rescues the functional expression of ΔF508CFTR by promoting F-actin organization and formation of the NHERF1-ezrin-actin complex. Here, using real-time FRET reporters of both PKA activity and cAMP levels, we find that lack of an organized subcortical cytoskeleton in CFBE41o-cells causes both defective accumulation of cAMP in the subcortical compartment and excessive cytosolic accumulation of cAMP. This results in reduced subcortical levels and increased cytosolic levels of PKA activity. NHERF1 overexpression in CFBE41o-cells restores chloride secretion, subcortical cAMP compartmentalization and local PKA activity, indicating that regulation of ΔF508CFTR function requires not only stable expression of the mutant CFTR at the cell surface but also depends on both generation of local cAMP signals of adequate amplitude and activation of PKA in proximity of its target. Moreover, we found that the knockdown of wild-type CFTR in the non-CF 16HBE14o-cells results in both altered cytoskeletal organization and loss of cAMP compartmentalization, whereas stable overexpression of wt CFTR in CF cells restores cytoskeleton organization and re-establishes the compartmentalization of cAMP at the plasma membrane. This suggests that the presence of CFTR on the plasma membrane influences the cytoskeletal organizational state and, consequently, cAMP distribution. Our data show that a sufficiently high concentration of cAMP in the subcortical compartment is required to achieve PKA-mediated regulation of CFTR activity.
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Affiliation(s)
- Stefania Monterisi
- Department of General and Environmental Physiology, University of Bari, Bari, 70125, Italy
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Innovations in the treatment of cystic fibrosis: outriders for the treatment of diseases with other genetic defects? Future Med Chem 2011; 3:1969-70. [PMID: 22098344 DOI: 10.4155/fmc.11.157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Roth EK, Hirtz S, Duerr J, Wenning D, Eichler I, Seydewitz HH, Amaral MD, Mall MA. The K+ channel opener 1-EBIO potentiates residual function of mutant CFTR in rectal biopsies from cystic fibrosis patients. PLoS One 2011; 6:e24445. [PMID: 21909392 PMCID: PMC3164200 DOI: 10.1371/journal.pone.0024445] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 08/10/2011] [Indexed: 12/05/2022] Open
Abstract
Background The identification of strategies to improve mutant CFTR function remains a key priority in the development of new treatments for cystic fibrosis (CF). Previous studies demonstrated that the K+ channel opener 1-ethyl-2-benzimidazolone (1-EBIO) potentiates CFTR-mediated Cl− secretion in cultured cells and mouse colon. However, the effects of 1-EBIO on wild-type and mutant CFTR function in native human colonic tissues remain unknown. Methods We studied the effects of 1-EBIO on CFTR-mediated Cl− secretion in rectal biopsies from 47 CF patients carrying a wide spectrum of CFTR mutations and 57 age-matched controls. Rectal tissues were mounted in perfused micro-Ussing chambers and the effects of 1-EBIO were compared in control tissues, CF tissues expressing residual CFTR function and CF tissues with no detectable Cl− secretion. Results Studies in control tissues demonstrate that 1-EBIO activated CFTR-mediated Cl− secretion in the absence of cAMP-mediated stimulation and potentiated cAMP-induced Cl− secretion by 39.2±6.7% (P<0.001) via activation of basolateral Ca2+-activated and clotrimazole-sensitive KCNN4 K+ channels. In CF specimens, 1-EBIO potentiated cAMP-induced Cl− secretion in tissues with residual CFTR function by 44.4±11.5% (P<0.001), but had no effect on tissues lacking CFTR-mediated Cl−conductance. Conclusions We conclude that 1-EBIO potentiates Cl−secretion in native CF tissues expressing CFTR mutants with residual Cl− channel function by activation of basolateral KCNN4 K+ channels that increase the driving force for luminal Cl− exit. This mechanism may augment effects of CFTR correctors and potentiators that increase the number and/or activity of mutant CFTR channels at the cell surface and suggests KCNN4 as a therapeutic target for CF.
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Affiliation(s)
- Eva K. Roth
- Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Department of Pediatrics III, University of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center, University of Heidelberg, Heidelberg, Germany
| | - Stephanie Hirtz
- Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Department of Pediatrics III, University of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center, University of Heidelberg, Heidelberg, Germany
| | - Julia Duerr
- Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Department of Pediatrics III, University of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center, University of Heidelberg, Heidelberg, Germany
| | - Daniel Wenning
- Pediatric Gastroenterology and Hepatology, Department of Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Irmgard Eichler
- Department of Pediatrics and Adolescent Medicine, University of Vienna, Vienna, Austria
| | - Hans H. Seydewitz
- Department of Pediatrics and Adolescent Medicine, Albert Ludwigs University, Freiburg, Germany
| | - Margarida D. Amaral
- Centre of Human Genetics, National Institute of Health Dr. Ricardo Jorge, Lisboa, Portugal
- Department of Chemistry and Biochemistry, Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Marcus A. Mall
- Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Department of Pediatrics III, University of Heidelberg, Heidelberg, Germany
- Translational Lung Research Center, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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Namkung W, Yao Z, Finkbeiner WE, Verkman AS. Small-molecule activators of TMEM16A, a calcium-activated chloride channel, stimulate epithelial chloride secretion and intestinal contraction. FASEB J 2011; 25:4048-62. [PMID: 21836025 DOI: 10.1096/fj.11-191627] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
TMEM16A (ANO1) is a calcium-activated chloride channel (CaCC) expressed in secretory epithelia, smooth muscle, and other tissues. Cell-based functional screening of ∼110,000 compounds revealed compounds that activated TMEM16A CaCC conductance without increasing cytoplasmic Ca(2+). By patch-clamp, N-aroylaminothiazole "activators" (E(act)) strongly increased Cl(-) current at 0 Ca(2+), whereas tetrazolylbenzamide "potentiators" (F(act)) were not active at 0 Ca(2+) but reduced the EC(50) for Ca(2+)-dependent TMEM16A activation. Of 682 analogs tested, the most potent activator (E(act)) and potentiator (F(act)) produced large and more sustained CaCC Cl(-) currents than general agonists of Ca(2+) signaling, with EC(50) 3-6 μM and Cl(-) conductance comparable to that induced transiently by Ca(2+)-elevating purinergic agonists. Analogs of activators were identified that fully inhibited TMEM16A Cl(-) conductance, providing further evidence for direct TMEM16A binding. The TMEM16A activators increased CaCC conductance in human salivary and airway submucosal gland epithelial cells, and IL-4 treated bronchial cells, and stimulated submucosal gland secretion in human bronchi and smooth muscle contraction in mouse intestine. Small-molecule, TMEM16A-targeted activators may be useful for drug therapy of cystic fibrosis, dry mouth, and gastrointestinal hypomotility disorders, and for pharmacological dissection of TMEM16A function.
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Affiliation(s)
- Wan Namkung
- Department of Medicine and Physiology, University of California, San Francisco, California 94143-0521, USA
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Caldwell RA, Grove DE, Houck SA, Cyr DM. Increased folding and channel activity of a rare cystic fibrosis mutant with CFTR modulators. Am J Physiol Lung Cell Mol Physiol 2011; 301:L346-52. [PMID: 21642448 DOI: 10.1152/ajplung.00044.2011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cystic fibrosis (CF) is a lethal recessive genetic disease caused by mutations in the CFTR gene. The gene product is a PKA-regulated anion channel that is important for fluid and electrolyte transport in the epithelia of lung, gut, and ducts of the pancreas and sweat glands. The most common CFTR mutation, ΔF508, causes a severe, but correctable, folding defect and gating abnormality, resulting in negligible CFTR function and disease. There are also a large number of rare CF-related mutations where disease is caused by CFTR misfolding. Yet the extent to which defective biogenesis of these CFTR mutants can be corrected is not clear. CFTRV232D is one such mutant that exhibits defective folding and trafficking. CFTRΔF508 misfolding is difficult to correct, but defective biogenesis of CFTRV232D is corrected to near wild-type levels by small-molecule folding correctors in development as CF therapeutics. To determine if CFTRV232D protein is competent as a Cl(-) channel, we utilized single-channel recordings from transfected human embryonic kidney (HEK-293) cells. After PKA stimulation, CFTRV232D channels were detected in patches with a unitary Cl(-) conductance indistinguishable from that of CFTR. Yet the frequency of detecting CFTRV232D channels was reduced to ∼20% of patches compared with 60% for CFTR. The folding corrector Corr-4a increased the CFTRV232D channel detection rate and activity to levels similar to CFTR. CFTRV232D-corrected channels were inhibited with CFTR(inh-172) and stimulated fourfold by the CFTR channel potentiator VRT-532. These data suggest that CF patients with rare mutations that cause CFTR misfolding, such as CFTRV232D, may benefit from treatment with folding correctors and channel potentiators in development to restore CFTRΔF508 function.
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Affiliation(s)
- Ray A Caldwell
- Dept. of Cell and Developmental Biology, Univ. of North Carolina, Chapel Hill, NC 27599, USA.
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Ibrahim BM, Tsifansky MD, Yang Y, Yeo Y. Challenges and advances in the development of inhalable drug formulations for cystic fibrosis lung disease. Expert Opin Drug Deliv 2011; 8:451-66. [PMID: 21375469 DOI: 10.1517/17425247.2011.561310] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Cystic fibrosis (CF) is a multisystem genetic disorder, which usually results in significant respiratory dysfunction. At present there is no cure for CF, but advances in pharmacotherapy have gradually increased the life expectancy of CF patients. As many drugs used in the therapy of CF are delivered by inhalation, the demand for effective and convenient inhalational CF drug formulations will grow as CF patients live longer. Knowledge of the current limitations in inhalational CF drug delivery is critical in identifying new opportunities and designing rational delivery strategies. AREAS COVERED This review discusses current and emerging therapeutic agents for CF therapy, selected physiological challenges to effective inhalational medication delivery, and various approaches to overcoming these challenges. The reader will find an integrated view of the known inhalational drug delivery challenges and the rationales for recent investigational inhalational drug formulations. EXPERT OPINION An ideal drug/gene delivery system to CF airways should overcome the tenacious sputum, which presents physical, chemical and biological barriers to effective transport of therapeutic agents to the targets and various cellular challenges.
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Affiliation(s)
- Basma M Ibrahim
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
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Noy E, Senderowitz H. Combating cystic fibrosis: in search for CF transmembrane conductance regulator (CFTR) modulators. ChemMedChem 2011; 6:243-51. [PMID: 21275046 DOI: 10.1002/cmdc.201000488] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Indexed: 11/05/2022]
Affiliation(s)
- Efrat Noy
- Department of Chemistry, Bar Ilan University, Ramat-Gan 52900, Israel
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