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Berges J, Graeber SY, Hämmerling S, Yu Y, Krümpelmann A, Stahl M, Hirtz S, Scheuermann H, Mall MA, Sommerburg O. Effects of lumacaftor-ivacaftor therapy on cystic fibrosis transmembrane conductance regulator function in F508del homozygous patients with cystic fibrosis aged 2-11 years. Front Pharmacol 2023; 14:1188051. [PMID: 37324488 PMCID: PMC10266342 DOI: 10.3389/fphar.2023.1188051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 05/18/2023] [Indexed: 06/17/2023] Open
Abstract
Rationale: Lumacaftor/ivacaftor was approved for the treatment of patients with cystic fibrosis who are homozygous for F508del aged 2 years and older following positive results from phase three trials. However, the improvement in CFTR function associated with lumacaftor/ivacaftor has only been studied in patients over 12 years of age, while the rescue potential in younger children is unknown. Methods: In a prospective study, we aimed to evaluate the effect of lumacaftor/ivacaftor on the CFTR biomarkers sweat chloride concentration and intestinal current measurement as well as clinical outcome parameters in F508del homozygous CF patients 2-11 years before and 8-16 weeks after treatment initiation. Results: A total of 13 children with CF homozygous for F508del aged 2-11 years were enrolled and 12 patients were analyzed. Lumacaftor/ivacaftor treatment reduced sweat chloride concentration by 26.8 mmol/L (p = 0.0006) and showed a mean improvement in CFTR activity, as assessed by intestinal current measurement in the rectal epithelium, of 30.5% compared to normal (p = 0.0015), exceeding previous findings of 17.7% of normal in CF patients homozygous for F508del aged 12 years and older. Conclusion: Lumacaftor/ivacaftor partially restores F508del CFTR function in children with CF who are homozygous for F508del, aged 2-11 years, to a level of CFTR activity seen in patients with CFTR variants with residual function. These results are consistent with the partial short-term improvement in clinical parameters.
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Affiliation(s)
- Julian Berges
- Division of Pediatric Pulmonology and Allergology and Cystic Fibrosis Center, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Simon Y. Graeber
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine and Cystic Fibrosis Center, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin Institute of Health at Charité—Universitätsmedizin Berlin, Berlin, Germany
- German Center for Lung Research (DZL), Associated Partner Site, Berlin, Germany
| | - Susanne Hämmerling
- Division of Pediatric Pulmonology and Allergology and Cystic Fibrosis Center, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Yin Yu
- Division of Pediatric Pulmonology and Allergology and Cystic Fibrosis Center, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Arne Krümpelmann
- Division of Pediatric Pulmonology and Allergology and Cystic Fibrosis Center, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Mirjam Stahl
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine and Cystic Fibrosis Center, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin Institute of Health at Charité—Universitätsmedizin Berlin, Berlin, Germany
- German Center for Lung Research (DZL), Associated Partner Site, Berlin, Germany
| | - Stephanie Hirtz
- Division of Pediatric Pulmonology and Allergology and Cystic Fibrosis Center, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Heike Scheuermann
- Division of Pediatric Pulmonology and Allergology and Cystic Fibrosis Center, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Marcus A. Mall
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine and Cystic Fibrosis Center, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin Institute of Health at Charité—Universitätsmedizin Berlin, Berlin, Germany
- German Center for Lung Research (DZL), Associated Partner Site, Berlin, Germany
| | - Olaf Sommerburg
- Division of Pediatric Pulmonology and Allergology and Cystic Fibrosis Center, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
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2
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Stanke F, Pallenberg ST, Tamm S, Hedtfeld S, Eichhorn EM, Minso R, Hansen G, Welte T, Sauer-Heilborn A, Ringshausen FC, Junge S, Tümmler B, Dittrich AM. Changes in cystic fibrosis transmembrane conductance regulator protein expression prior to and during elexacaftor-tezacaftor-ivacaftor therapy. Front Pharmacol 2023; 14:1114584. [PMID: 36778025 PMCID: PMC9911415 DOI: 10.3389/fphar.2023.1114584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/16/2023] [Indexed: 01/28/2023] Open
Abstract
Background: Defects in expression, maturation or function of the epithelial membrane glycoprotein CFTR are causative for the progressive disease cystic fibrosis. Recently, molecular therapeutics that improve CFTR maturation and functional defects have been approved. We aimed to verify whether we could detect an improvement of CFTR protein expression and maturation by triple therapy with elexacaftor-tezacaftor-ivacaftor (ELX/TEZ/IVA). Methods: Rectal suction biopsies of 21 p.Phe508del homozygous or compound heterozygous CF patients obtained pre- and during treatment with ELX/TEZ/IVA were analyzed by CFTR Western blot that was optimized to distinguish CFTR glycoisoforms. Findings: CFTR western immunoblot analysis revealed that-compared to baseline-the levels of CFTR protein increased by at least twofold in eight out of 12 patients upon treatment with ELX/TEZ/IVA compared to baseline (p < 0.02). However, polydispersity of the mutant CFTR protein was lower than that of the fully glycosylated wild type CFTR Golgi isoform, indicating an incompletely glycosylated p.Phe508el CFTR protein isoform C* in patients with CF which persists after ELX/TEZ/IVA treatment. Interpretation: Treatment with ELX/TEZ/IVA increased protein expression by facilitating the posttranslational processing of mutant CFTR but apparently did not succeed in generating the polydisperse spectrum of N-linked oligosaccharides that is characteristic for the wild type CFTR band C glycoisoform. Our results caution that the lower amounts or immature glycosylation of the C* glycoisoform observed in patients' biomaterial might not translate to fully restored function of mutant CFTR necessary for long-term provision of clinical benefit.
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Affiliation(s)
- Frauke Stanke
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany,*Correspondence: Frauke Stanke,
| | - Sophia T. Pallenberg
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Stephanie Tamm
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Silke Hedtfeld
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Ella M. Eichhorn
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Rebecca Minso
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Gesine Hansen
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Tobias Welte
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany,Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
| | | | - Felix C. Ringshausen
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany,Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
| | - Sibylle Junge
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Burkhard Tümmler
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Anna-Maria Dittrich
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany
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3
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Zakerska-Banaszak O, Gozdzik-Spychalska J, Gabryel M, Zuraszek J, Skrzypczak-Zielinska M, Slomski R, Dobrowolska A, Piorunek T, Batura-Gabryel H. IL1B gene variants, but not TNF, CXCL8, IL6 and IL10, modify the course of cystic fibrosis in Polish patients. F1000Res 2022; 11:379. [PMID: 39185143 PMCID: PMC11344199 DOI: 10.12688/f1000research.110472.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/21/2022] [Indexed: 08/27/2024] Open
Abstract
Background: The main aim of this study was to evaluate whether selected polymorphic variants in genes from the inflammatory pathway can be predictors of pulmonary or digestive manifestation of cystic fibrosis, as well as of severity of lung disease. Materials and methods: Using pyrosequencing and sequencing we have genotyped 12 variants in TNF (rs361525, rs1800629), CXCL8 (rs4073, rs2227306, rs2227307, rs188378669), IL1B (rs16944, rs1143634, rs1142639, rs1143627), IL6 (rs1800795) and IL10 (rs1800896) genes in a cohort of 55 Polish patients with diagnosed cystic fibrosis and controls. In our study group, a pulmonary manifestation of disease revealed 44 of subjects (80%), and digestive symptoms dominated in 11 (20%) of analyzed individuals. Severe lung dysfunction has occurred in 20 (36.4%) of patients. Results: We proved, that two promoter variants of IL1B, rs1143627 (c.-118G > A) and rs16944 (c.-598T > C) are presented significantly more often in patients with severe character of lung disease compared to mild (82.5% vs. 62.8%, p-value 0.030, and 87.5% vs. 64.3%, p-value 0.008, respectively) in cystic fibrosis course. Haplotype AC formed by both changes had also a higher frequency (80%) in patients with severe course compared to the mild character (61.4%) of disease. However, the frequency of promoter variant TNF c.-308C > T (rs1800629) was presented at a significantly lower level in the patient's group compared to healthy controls (2.7% vs. 15%, p-value 0.001). Furthermore, the presence of methicillin-resistant Staphylococcus aureus significantly correlated with the lower FEV1% in patients (p-value 0.01). Conclusions: Genetic variants, rs1143627 and rs16944, of IL1B are promising candidates as predictors of the severe character of lung disease in Polish patients with cystic fibrosis.
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Affiliation(s)
| | - Joanna Gozdzik-Spychalska
- Department of Pulmonology, Allergology and Lung Oncology, Poznan University of Medical Sciences, Poznań, Poland
| | - Marcin Gabryel
- Department of Gastroenterology, Dietetics and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland
| | - Joanna Zuraszek
- Institute of Human Genetics Polish Academy of Sciences, Poznan, Poland
| | | | - Ryszard Slomski
- Institute of Human Genetics Polish Academy of Sciences, Poznan, Poland
| | - Agnieszka Dobrowolska
- Department of Gastroenterology, Dietetics and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland
| | - Tomasz Piorunek
- Department of Pulmonology, Allergology and Lung Oncology, Poznan University of Medical Sciences, Poznań, Poland
| | - Halina Batura-Gabryel
- Department of Pulmonology, Allergology and Lung Oncology, Poznan University of Medical Sciences, Poznań, Poland
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Schamschula E, Lahnsteiner A, Assenov Y, Hagmann W, Zaborsky N, Wiederstein M, Strobl A, Stanke F, Muley T, Plass C, Tümmler B, Risch A. Disease-related blood-based differential methylation in cystic fibrosis and its representation in lung cancer revealed a regulatory locus in PKP3 in lung epithelial cells. Epigenetics 2021; 17:837-860. [PMID: 34415821 PMCID: PMC9423854 DOI: 10.1080/15592294.2021.1959976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cystic fibrosis (CF) is a monogenic disease, characterized by massive chronic lung inflammation. The observed variability in clinical phenotypes in monozygotic CF twins is likely associated with the extent of inflammation. This study sought to investigate inflammation-related aberrant DNA methylation in CF twins and to determine to what extent acquired methylation changes may be associated with lung cancer. Blood-based genome-wide DNA methylation analysis was performed to compare the DNA methylomes of monozygotic twins, from the European CF Twin and Sibling Study with various degrees of disease severity. Putatively inflammation-related and differentially methylated positions were selected from a large lung cancer case-control study and investigated in blood by targeted bisulphite next-generation-sequencing. An inflammation-related locus located in the Plakophilin-3 (PKP3) gene was functionally analysed regarding promoter and enhancer activity in presence and absence of methylation using luciferase reporter assays. We confirmed in a unique cohort that monozygotic twins, even if clinically discordant, have only minor differences in global DNA methylation patterns and blood cell composition. Further, we determined the most differentially methylated positions, a high proportion of which are blood cell-type-specific, whereas others may be acquired and thus have potential relevance in the context of inflammation as lung cancer risk factors. We identified a sequence in the gene body of PKP3 which is hypermethylated in blood from CF twins with severe phenotype and highly variably methylated in lung cancer patients and controls, independent of known clinical parameters, and showed that this region exhibits methylation-dependent promoter activity in lung epithelial cells.
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Affiliation(s)
| | | | - Yassen Assenov
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Wolfgang Hagmann
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Nadja Zaborsky
- Department of Internal Medicine III with Haematology, Medical Oncology, Haemostaseology, Infectiology and Rheumatology, Oncologic Center, Salzburg Cancer Research Institute - Laboratory for Immunological and Molecular Cancer Research (SCRI-LIMCR), Paracelsus Medical University, Salzburg, Austria.,Cancer Cluster Salzburg, Salzburg, Austria
| | | | - Anna Strobl
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Frauke Stanke
- Clinical Research Group, Clinic for Pediatric Pneumology, Allergology and NeonatologyClinic for Pediatric Pneumology, Allergology and Neonatology, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Thomas Muley
- Translational Research Unit, Thoraxklinik Heidelberg, University of Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| | - Christoph Plass
- Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| | - Burkhard Tümmler
- Clinical Research Group, Clinic for Pediatric Pneumology, Allergology and NeonatologyClinic for Pediatric Pneumology, Allergology and Neonatology, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Angela Risch
- Department of Biosciences, University of Salzburg, Salzburg, Austria.,Division of Cancer Epigenomics, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Cancer Cluster Salzburg, Salzburg, Austria.,Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
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5
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Marx DC, Fleming KG. Membrane proteins enter the fold. Curr Opin Struct Biol 2021; 69:124-130. [PMID: 33975156 DOI: 10.1016/j.sbi.2021.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/15/2021] [Accepted: 03/21/2021] [Indexed: 11/19/2022]
Abstract
Membrane proteins have historically been recalcitrant to biophysical folding studies. However, recent adaptations of methods from the soluble protein folding field have found success in their applications to transmembrane proteins composed of both α-helical and β-barrel conformations. Avoiding aggregation is critical for the success of these experiments. Altogether these studies are leading to discoveries of folding trajectories, foundational stabilizing forces and better-defined endpoints that enable more accurate interpretation of thermodynamic data. Increased information on membrane protein folding in the cell shows that the emerging biophysical principles are largely recapitulated even in the complex biological environment.
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Affiliation(s)
- Dagan C Marx
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21218, United States
| | - Karen G Fleming
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21218, United States.
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6
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Genetic information from discordant sibling pairs points to ESRP2 as a candidate trans-acting regulator of the CF modifier gene SCNN1B. Sci Rep 2020; 10:22447. [PMID: 33384439 PMCID: PMC7775467 DOI: 10.1038/s41598-020-79804-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 12/10/2020] [Indexed: 11/08/2022] Open
Abstract
SCNN1B encodes the beta subunit of the epithelial sodium channel ENaC. Previously, we reported an association between SNP markers of SCNN1B gene and disease severity in cystic fibrosis-affected sibling pairs. We hypothesized that factors interacting with the SCNN1B genomic sequence are responsible for intrapair discordance. Concordant and discordant pairs differed at six SCNN1B markers (Praw = 0.0075, Pcorr = 0.0397 corrected for multiple testing). To identify the factors binding to these six SCNN1B SNPs, we performed an electrophoretic mobility shift assay and captured the DNA-protein complexes. Based on protein mass spectrometry data, the epithelial splicing regulatory protein ESRP2 was identified when using SCNN1B-derived probes and the ESRP2-SCNN1B interaction was independently confirmed by coimmunoprecipitation assays. We observed an alternative SCNN1B transcript and demonstrated in 16HBE14o- cells that levels of this transcript are decreased upon ESRP2 silencing by siRNA. Furthermore, we confirmed that mildly and severely affected siblings have different ESPR2 genetic backgrounds and that ESRP2 markers are linked to the response of CF patients' nasal epithelium to amiloride, indicating ENaC involvement (Pbest = 0.0131, Pcorr = 0.068 for multiple testing). Our findings demonstrate that sibling pairs clinically discordant for CF can be used to identify meaningful DNA regulatory elements and interacting factors.
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7
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Forskolin-induced swelling of intestinal organoids correlates with disease severity in adults with cystic fibrosis and homozygous F508del mutations. J Cyst Fibros 2019; 19:614-619. [PMID: 31735562 DOI: 10.1016/j.jcf.2019.10.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 10/01/2019] [Accepted: 10/22/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND CFTR function measurements in intestinal organoids may help to better characterise individual disease expression in F508del homozygous people. Our objective was to study correlations between CFTR function as measured with forskolin-induced swelling in rectal organoids with clinical parameters in adult patients with homozygous F508del mutations. METHODS Multicentre observational study. Thirty-four adults underwent rectal biopsy, pulmonary function tests (FEV1 and FVC), chest X-ray and chest CT. Body-mass index (BMI) was assessed at study visit and exacerbation rate was determined during five years prior to study visit. Organoids were cultured and measured after stimulation with 5 µm forskolin for three hours to quantitate CFTR residual function. FINDINGS FIS was positively correlated with FEV1 (r = 0.36, 95% CI 0.02-0.62, p = 0.04) and BMI (r = 0.42, 95% CI 0.09-0.66, p = 0.015). FIS was negatively correlated with PRAGMA-CF CT score for% of disease (r = -0.37, 95% CI -0.62- -0.03, p = 0.049). We found no significant correlation between FIS and chest radiography score for CF (r = -0.16, 95% CI -0.48-0.20, p = 0.44). We observed a trend between higher FIS and a lower mean number of exacerbations over the last 5 years of observation, but this was not statistically significant (Poisson regression, p = 0.089). INTERPRETATION FIS of intestinal organoids varied between subjects with homozygous F508del and correlated with pulmonary and nutritional parameters. These findings suggest that differences at low CFTR residual function may contribute to clinical heterogeneity in F508del homozygous patients and small changes in CFTR residual function might impact long-term disease expression.
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8
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Favia M, de Bari L, Bobba A, Atlante A. An Intriguing Involvement of Mitochondria in Cystic Fibrosis. J Clin Med 2019; 8:jcm8111890. [PMID: 31698802 PMCID: PMC6912654 DOI: 10.3390/jcm8111890] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 10/31/2019] [Accepted: 11/04/2019] [Indexed: 12/16/2022] Open
Abstract
Cystic fibrosis (CF) occurs when the cystic fibrosis transmembrane conductance regulator (CFTR) protein is not synthetized and folded correctly. The CFTR protein helps to maintain the balance of salt and water on many body surfaces, such as the lung surface. When the protein is not working correctly, chloride becomes trapped in cells, then water cannot hydrate the cellular surface and the mucus covering the cells becomes thick and sticky. Furthermore, a defective CFTR appears to produce a redox imbalance in epithelial cells and extracellular fluids and to cause an abnormal generation of reactive oxygen species: as a consequence, oxidative stress has been implicated as a causative factor in the aetiology of the process. Moreover, massive evidences show that defective CFTR gives rise to extracellular GSH level decrease and elevated glucose concentrations in airway surface liquid (ASL), thus encouraging lung infection by pathogens in the CF advancement. Recent research in progress aims to rediscover a possible role of mitochondria in CF. Here the latest new and recent studies on mitochondrial bioenergetics are collected. Surprisingly, they have enabled us to ascertain that mitochondria have a leading role in opposing the high ASL glucose level as well as oxidative stress in CF.
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Affiliation(s)
- Maria Favia
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari—CNR, Via G. Amendola 122/O, 70126 Bari, Italy; (L.d.B.); (A.B.)
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università di Bari, Via E. Orabona 4, 70126 Bari, Italy
- Correspondence: (M.F.); (A.A.)
| | - Lidia de Bari
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari—CNR, Via G. Amendola 122/O, 70126 Bari, Italy; (L.d.B.); (A.B.)
| | - Antonella Bobba
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari—CNR, Via G. Amendola 122/O, 70126 Bari, Italy; (L.d.B.); (A.B.)
| | - Anna Atlante
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari—CNR, Via G. Amendola 122/O, 70126 Bari, Italy; (L.d.B.); (A.B.)
- Correspondence: (M.F.); (A.A.)
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9
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Graeber SY, Dopfer C, Naehrlich L, Gyulumyan L, Scheuermann H, Hirtz S, Wege S, Mairbäurl H, Dorda M, Hyde R, Bagheri-Hanson A, Rueckes-Nilges C, Fischer S, Mall MA, Tümmler B. Effects of Lumacaftor-Ivacaftor Therapy on Cystic Fibrosis Transmembrane Conductance Regulator Function in Phe508del Homozygous Patients with Cystic Fibrosis. Am J Respir Crit Care Med 2019; 197:1433-1442. [PMID: 29327948 DOI: 10.1164/rccm.201710-1983oc] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
RATIONALE The combination of the CFTR (cystic fibrosis transmembrane conductance regulator) corrector lumacaftor with the potentiator ivacaftor has been approved for the treatment of patients with cystic fibrosis homozygous for the Phe508del CFTR mutation. The phase 3 trials examined clinical outcomes but did not evaluate CFTR function in patients. OBJECTIVES To examine the effect of lumacaftor-ivacaftor on biomarkers of CFTR function in Phe508del homozygous patients with cystic fibrosis aged 12 years and older. METHODS This prospective observational study assessed clinical outcomes including FEV1% predicted and body mass index, and CFTR biomarkers including sweat chloride concentration, nasal potential difference, and intestinal current measurement before and 8-16 weeks after initiation of lumacaftor-ivacaftor. MEASUREMENTS AND MAIN RESULTS A total of 53 patients were enrolled in the study, and 52 patients had baseline and follow-up measurements. After initiation of lumacaftor-ivacaftor sweat chloride concentrations were reduced by 17.8 mmol/L (interquartile range [IQR], -25.9 to -6.1; P < 0.001), nasal potential difference showed partial rescue of CFTR function in nasal epithelia to a level of 10.2% (IQR, 0.0-26.1; P < 0.011), and intestinal current measurement showed functional improvement in rectal epithelia to a level of 17.7% of normal (IQR, 10.8-29.0; P < 0.001). All patients improved in at least one CFTR biomarker, but no correlations were found between CFTR biomarker responses and clinical outcomes. CONCLUSIONS Lumacaftor-ivacaftor results in partial rescue of Phe508del CFTR function to levels comparable to the lower range of CFTR activity found in patients with residual function mutations. Functional improvement was detected even in the absence of short-term improvement of FEV1% predicted and body mass index. Clinical trial registered with www.clinicaltrials.gov (NCT02807415).
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Affiliation(s)
- Simon Y Graeber
- 1 Department of Translational Pulmonology.,2 Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Department of Pediatrics, and.,3 Translational Lung Research Center Heidelberg, German Center for Lung Research, University of Heidelberg, Heidelberg, Germany.,4 Department of Pediatric Pulmonology and Immunology and Cystic Fibrosis Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Christian Dopfer
- 5 Clinic of Pediatric Pneumology, Allergology, and Neonatology and.,6 Biomedical Research in Endstage and Obstructive Lung Disease Hannover, German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Lutz Naehrlich
- 7 Department of Pediatrics, Justus-Liebig-University Giessen, Giessen, Germany.,8 Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Lena Gyulumyan
- 5 Clinic of Pediatric Pneumology, Allergology, and Neonatology and
| | | | | | - Sabine Wege
- 9 Department of Pneumology and Respiratory Critical Care Medicine, Thoraxklinik, University Hospital Heidelberg, Heidelberg, Germany; and
| | - Heimo Mairbäurl
- 3 Translational Lung Research Center Heidelberg, German Center for Lung Research, University of Heidelberg, Heidelberg, Germany.,9 Department of Pneumology and Respiratory Critical Care Medicine, Thoraxklinik, University Hospital Heidelberg, Heidelberg, Germany; and.,10 Medical Clinic VII, Sports Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Marie Dorda
- 5 Clinic of Pediatric Pneumology, Allergology, and Neonatology and.,6 Biomedical Research in Endstage and Obstructive Lung Disease Hannover, German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Rebecca Hyde
- 5 Clinic of Pediatric Pneumology, Allergology, and Neonatology and.,6 Biomedical Research in Endstage and Obstructive Lung Disease Hannover, German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | | | - Claudia Rueckes-Nilges
- 7 Department of Pediatrics, Justus-Liebig-University Giessen, Giessen, Germany.,8 Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Sebastian Fischer
- 5 Clinic of Pediatric Pneumology, Allergology, and Neonatology and.,6 Biomedical Research in Endstage and Obstructive Lung Disease Hannover, German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Marcus A Mall
- 1 Department of Translational Pulmonology.,2 Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Department of Pediatrics, and.,3 Translational Lung Research Center Heidelberg, German Center for Lung Research, University of Heidelberg, Heidelberg, Germany.,4 Department of Pediatric Pulmonology and Immunology and Cystic Fibrosis Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Burkhard Tümmler
- 5 Clinic of Pediatric Pneumology, Allergology, and Neonatology and.,6 Biomedical Research in Endstage and Obstructive Lung Disease Hannover, German Center for Lung Research, Hannover Medical School, Hannover, Germany
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Malone H, Biggar S, Javadpour S, Edworthy Z, Sheaf G, Coyne I. Interventions for promoting participation in shared decision-making for children and adolescents with cystic fibrosis. Cochrane Database Syst Rev 2019; 5:CD012578. [PMID: 31119726 PMCID: PMC6531890 DOI: 10.1002/14651858.cd012578.pub2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Shared decision-making is important in child and adolescent healthcare because there is growing international recognition of children and young people's rights to be included in decisions that affect them. In order for young people to participate effectively in shared decision-making they need to develop the skills of engagement with healthcare professionals and confidence in interacting with them. They also need to learn how to manage their condition and treatments on their own when they move into adulthood. Children and young people who participate in shared decision-making in healthcare are likely to be more informed, feel more prepared, and experience less anxiety about the unknown. Significant improvements in cystic fibrosis (CF) survival over recent decades, due to improved therapies and better management of care, means that young people with CF are routinely transitioning to adult healthcare where increasing emphasis on self-management brings greater complexity in decision-making. We need to know what interventions are effective in promoting shared decision-making for young people with CF. OBJECTIVES To assess the effectiveness of interventions that promote participation in shared decision-making for children and adolescents (aged between four and 18 years) with CF. SEARCH METHODS We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearches of journals and conference abstract books. We also searched the reference lists of articles and reviews addressing shared decision-making.Date of most recent search: 12 March 2019.We searched PubMed, CINAHL (EBSCO), Embase (Elsevier), PsycINFO (EBSCO), WHO ICTRP, ASSIA (ProQuest), ERIC (ProQuest), ProQuest Dissertations and Theses, and ClinicalTrials.gov. We contacted study authors with published relevant research in shared decision-making for adults to ask if they were aware of any published or ongoing studies on the promotion of the intervention for children or adolescents (or both) with CF.Date of most recent search: 19 March 2019. SELECTION CRITERIA We planned to include randomised controlled trials (RCTs) (but not cross-over RCTs) of interventions promoting shared decision-making for children and adolescents with CF aged between four and 18 years, such as information provision, booklets, two-way interaction, checking understanding (by the participant), preparation to participate in a healthcare decision, decision-aids, and training interventions or educational programs. We planned to include interventions aimed at children or adolescents (or both), parents or healthcare professionals or any combination of these groups provided that the focus was aimed at promoting shared decision-making for children and adolescents with CF. DATA COLLECTION AND ANALYSIS Two authors independently reviewed papers identified in the searches. MAIN RESULTS No eligible RCTs were identified for inclusion in this systematic review. AUTHORS' CONCLUSIONS We were unable to identify RCTs with evidence which would support healthcare policy-making and practice related to implementation of shared decision-making for children and adolescents (aged between four and 18 years) with CF). We hope that having identified this gap in research, awareness will increase amongst researchers of the need to design high-quality shared decision-making interventions for young people with CF, perhaps adapted from existing models for adults, and to test these interventions and children's preferences in RCTs. It is also important to target health professionals with evidence-based education programmes on shared decision-making and a need for international consensus on addressing the variability in education programmes.
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Affiliation(s)
- Helen Malone
- Trinity College DublinSchool of Nursing & Midwifery24 D’Olier Street, College GreenDublin 2Ireland
| | - Susan Biggar
- Australian Health Practitioner Regulation Agency (AHPRA)111 Burke Street, Level 7MelbourneAustraliaVIC 3000
| | - Sheila Javadpour
- Our Lady's Children's Hospital, CrumlinDepartment of Respiratory MedicineDublinIreland12
| | - Zai Edworthy
- Temple Street Children's University HospitalDepartment of PsychologyTemple StreetDublinIrelandDO1 YC67
| | - Greg Sheaf
- The Library of Trinity College DublinCollege StreetDublinIreland
| | - Imelda Coyne
- Trinity College DublinSchool of Nursing & Midwifery24 D'Olier StDublinIreland2
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Chaperones rescue the energetic landscape of mutant CFTR at single molecule and in cell. Nat Commun 2017; 8:398. [PMID: 28855508 PMCID: PMC5577305 DOI: 10.1038/s41467-017-00444-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 06/29/2017] [Indexed: 12/14/2022] Open
Abstract
Molecular chaperones are pivotal in folding and degradation of the cellular proteome but their impact on the conformational dynamics of near-native membrane proteins with disease relevance remains unknown. Here we report the effect of chaperone activity on the functional conformation of the temperature-sensitive mutant cystic fibrosis channel (∆F508-CFTR) at the plasma membrane and after reconstitution into phospholipid bilayer. Thermally induced unfolding at 37 °C and concomitant functional inactivation of ∆F508-CFTR are partially suppressed by constitutive activity of Hsc70 and Hsp90 chaperone/co-chaperone at the plasma membrane and post-endoplasmic reticulum compartments in vivo, and at single-molecule level in vitro, indicated by kinetic and thermodynamic remodeling of the mutant gating energetics toward its wild-type counterpart. Thus, molecular chaperones can contribute to functional maintenance of ∆F508-CFTR by reshaping the conformational energetics of its final fold, a mechanism with implication in the regulation of metastable ABC transporters and other plasma membrane proteins activity in health and diseases. The F508 deletion (F508del) in the cystic fibrosis transmembrane conductance regulator (CFTR) is the most common CF causing mutation. Here the authors show that cytosolic chaperones shift the F508del channel conformation to the native fold by kinetic and thermodynamic remodelling of the gating energetics towards that of wild-type CTFR.
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12
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In silico search for modifier genes associated with pancreatic and liver disease in Cystic Fibrosis. PLoS One 2017; 12:e0173822. [PMID: 28339466 PMCID: PMC5365109 DOI: 10.1371/journal.pone.0173822] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 02/27/2017] [Indexed: 12/15/2022] Open
Abstract
Cystic Fibrosis is the most common lethal autosomal recessive disorder in the white population, affecting among other organs, the lung, the pancreas and the liver. Whereas Cystic Fibrosis is a monogenic disease, many studies reveal a very complex relationship between genotype and clinical phenotype. Indeed, the broad phenotypic spectrum observed in Cystic Fibrosis is far from being explained by obvious genotype-phenotype correlations and it is admitted that Cystic Fibrosis disease is the result of multiple factors, including effects of the environment as well as modifier genes. Our objective was to highlight new modifier genes with potential implications in the lung, pancreatic and liver outcomes of the disease. For this purpose we performed a system biology approach which combined, database mining, literature mining, gene expression study and network analysis as well as pathway enrichment analysis and protein-protein interactions. We found that IFI16, CCNE2 and IGFBP2 are potential modifiers in the altered lung function in Cystic Fibrosis. We also found that EPHX1, HLA-DQA1, HLA-DQB1, DSP and SLC33A1, GPNMB, NCF2, RASGRP1, LGALS3 and PTPN13, are potential modifiers in pancreas and liver, respectively. Associated pathways indicate that immune system is likely involved and that Ubiquitin C is probably a central node, linking Cystic Fibrosis to liver and pancreatic disease. We highlight here new modifier genes with potential implications in Cystic Fibrosis. Nevertheless, our in silico analysis requires functional analysis to give our results a physiological relevance.
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Malone H, Biggar S, Javadpour S, Edworthy Z, Sheaf G, Coyne I. Interventions for promoting participation in shared decision-making for children and adolescents with cystic fibrosis. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2017. [DOI: 10.1002/14651858.cd012578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Helen Malone
- Trinity College Dublin; School of Nursing & Midwifery; 24 D’Olier Street, College Green Dublin Ireland 2
| | - Susan Biggar
- Health Issues Centre; Consumer Partnerships; 255 Bourke Street Melbourne Victoria Australia VIC 3000
| | - Sheila Javadpour
- Our Lady's Children's Hospital, Crumlin; Department of Respiratory Medicine; Dublin Ireland 12
| | - Zai Edworthy
- Temple Street Children's University Hospital; Department of Psychology; Temple Street Dublin Ireland DO1 YC67
| | - Greg Sheaf
- The Library of Trinity College Dublin; College Street Dublin Ireland
| | - Imelda Coyne
- Trinity College Dublin; School of Nursing & Midwifery; 24 D’Olier Street, College Green Dublin Ireland 2
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14
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Comparison of Nasal Potential Difference and Intestinal Current Measurements as Surrogate Markers for CFTR Function. J Pediatr Gastroenterol Nutr 2016; 63:e92-e97. [PMID: 27496797 DOI: 10.1097/mpg.0000000000001366] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Nasal potential difference (NPD) measurement is part of the diagnostic criteria for cystic fibrosis (CF) and now used routinely as an endpoint in clinical trials of correcting the basic defect in CF. Intestinal current measurement (ICM), measured ex vivo on a rectal biopsy, has been used to study cystic fibrosis transmembrane conductance regulator (CFTR) function but has not been compared to NPD in the same subject in adults and children. The aim of the study is to evaluate the potential usefulness of ICM as a marker of CFTR function for treatment studies compared NPD in patients with CF and in healthy control subjects. METHODS ICM and NPD were performed on healthy controls and patients with CF. The healthy adults were individuals undergoing routine screening colonoscopy at the Beth Israel Deaconess Medical Center. The healthy children were undergoing colonoscopy for suspicion of inflammation in Hadassah Hebrew University Medical Center. The CF adults were recruited from Boston Children's Hospital CF Center and CF Center Worcester Mass, the children with CF from Hadassah CF Center. RESULTS ICM measurements in healthy control subjects (n = 16) demonstrated a mean (±SE) carbachol response of 16.0 (2.2) μA/cm, histamine response of 13.2 (2.1) μA/cm and a forskolin response of 6.3 (2.0) μA/cm. Basal NPD of -15.9 (1.9) and response to Cl free + isoproterenol of -13.8 (2.0). These responses were inverted in CF subjects (n = 12) for ICM parameters with carbachol response of -3.0 (0.5) μA/cm, histamine -1.0 (0.8) μA/cm and a forskolin response of 0.5 (0.3) and also for NPD parameters; basal NPD of -42.2 (4.3) and response to Cl free + isoproterenol of 4.3 (0.7). Pearson correlation test showed the comparability of ICM and NPD in assessing CFTR function. CONCLUSIONS ICM is equivalent to NPD in the ability to distinguish patients with CF from controls and could be used as surrogate markers of CFTR activity in treatment protocols.
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15
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Beekman JM. Individualized medicine using intestinal responses to CFTR potentiators and correctors. Pediatr Pulmonol 2016; 51:S23-S34. [PMID: 27662101 DOI: 10.1002/ppul.23553] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 07/22/2016] [Accepted: 07/25/2016] [Indexed: 12/14/2022]
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) modulators that target the mutant CFTR protein are being introduced for treatment of cystic fibrosis. Stratification of subjects based on their CFTR genotype has been proven essential to demonstrate clinical efficacy of these novel treatments. Despite this stratification, considerable heterogeneity between subjects receiving CFTR modulators is still observed which remains largely uncharacterized. The CFTR genotype, and additional genetic and environmental factors that impact either tissue-specific CFTR protein characteristics or the pharmacokinetic properties of treatments will likely determine the individual response to therapy. The development of intestinal biomarkers for CFTR modulators may help to better quantitate individual responses to treatment, with potential to optimize treatments for subjects with limited responses, and the selection of responsive subjects that currently do not receive treatments. Here, recent advances concerning the use of intestinal biomarkers for CFTR modulator treatments are reviewed, with a focus on biomarkers of CFTR function in ex vivo rectal biopsies and in vitro cultured primary intestinal organoids. Their potential value is considered in the context of the current unmet needs for better treatments for the majority of subjects with CF, and individual biomarkers that enable the prediction of long term therapeutic responses to CFTR modulators. Pediatr Pulmonol. 2016;51:S23-S34. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Jeffrey M Beekman
- Department of Pediatric Pulmonology, Wilhelmina Children's Hospital, Regenerative Medical Center, University Medical Center Utrecht, Utrecht, The Netherlands.
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16
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Abstract
Whilst cystic fibrosis is a monogenic condition, variation in phenotype exists for the same CFTR genotype, which is influenced by multiple genetic and non-genetic (environmental) factors. The R117H-CFTR mutation has variability directly relating to in cis poly-thymidine alleles, producing a differing spectrum of disease. This paper provides evidence of extreme phenotype variability - including fertility status - in the context of male monogenetic twins, discussing mechanisms and highlighting the diagnostic and treatment challenges.
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Affiliation(s)
- Michael D Waller
- Adult Cystic Fibrosis Centre, Royal Brompton and Harefield NHS Foundation Trust, Sydney Street, London, UK, SW3 6NP.
| | - Nicholas J Simmonds
- Adult Cystic Fibrosis Centre, Royal Brompton and Harefield NHS Foundation Trust, Sydney Street, London, UK, SW3 6NP
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Colemeadow J, Joyce H, Turcanu V. Precise treatment of cystic fibrosis – current treatments and perspectives for using CRISPR. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2016. [DOI: 10.1080/23808993.2016.1146077] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Corvol H, Thompson KE, Tabary O, le Rouzic P, Guillot L. Translating the genetics of cystic fibrosis to personalized medicine. Transl Res 2016; 168:40-49. [PMID: 25940043 DOI: 10.1016/j.trsl.2015.04.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 04/08/2015] [Accepted: 04/09/2015] [Indexed: 01/06/2023]
Abstract
Cystic fibrosis (CF) is the most common life-threatening recessive genetic disease in the Caucasian population. This multiorgan disease is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein, a chloride channel recognized as regulating several apical ion channels. The gene mutations result either in the lack of the protein at the apical surface or in an improperly functioning protein. Morbidity and mortality because of the mutation of CFTR are mainly attributable to lung disease resulting from chronic infection and inflammation. Since its discovery as the causative gene in 1989, much progress has been achieved not only in clinical genetics but also in basic science studies. Recently, combinations of these efforts have been successfully translated into development and availability for patients of new therapies targeting specific CFTR mutations to correct the CFTR at the protein level. Current technologies such as next gene sequencing and novel genomic editing tools may offer new strategies to identify new CFTR variants and modifier genes, and to correct CFTR to pursue personalized medicine, which is already developed in some patient subsets. Personalized medicine or P4 medicine ("personalized," "predictive," "preventive," and "participatory") is currently booming for CF. The various current and future challenges of personalized medicine as they apply to the issues faced in CF are discussed in this review.
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Affiliation(s)
- Harriet Corvol
- INSERM, UMR_S 938, CDR Saint-Antoine, Paris, France; Sorbonne Universités, UPMC University Paris 06, UMR_S 938, CDR Saint-Antoine, Paris, France; Pneumologie pédiatrique, APHP, Hôpital Trousseau, Paris, France
| | - Kristin E Thompson
- INSERM, UMR_S 938, CDR Saint-Antoine, Paris, France; Sorbonne Universités, UPMC University Paris 06, UMR_S 938, CDR Saint-Antoine, Paris, France
| | - Olivier Tabary
- INSERM, UMR_S 938, CDR Saint-Antoine, Paris, France; Sorbonne Universités, UPMC University Paris 06, UMR_S 938, CDR Saint-Antoine, Paris, France
| | - Philippe le Rouzic
- INSERM, UMR_S 938, CDR Saint-Antoine, Paris, France; Sorbonne Universités, UPMC University Paris 06, UMR_S 938, CDR Saint-Antoine, Paris, France
| | - Loïc Guillot
- INSERM, UMR_S 938, CDR Saint-Antoine, Paris, France; Sorbonne Universités, UPMC University Paris 06, UMR_S 938, CDR Saint-Antoine, Paris, France.
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Veit G, Avramescu RG, Perdomo D, Phuan PW, Bagdany M, Apaja PM, Borot F, Szollosi D, Wu YS, Finkbeiner WE, Hegedus T, Verkman AS, Lukacs GL. Some gating potentiators, including VX-770, diminish ΔF508-CFTR functional expression. Sci Transl Med 2015; 6:246ra97. [PMID: 25101887 DOI: 10.1126/scitranslmed.3008889] [Citation(s) in RCA: 240] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane regulator (CFTR) that result in reduced anion conductance at the apical membrane of secretory epithelia. Treatment of CF patients carrying the G551D gating mutation with the potentiator VX-770 (ivacaftor) largely restores channel activity and has shown substantial clinical benefit. However, most CF patients carry the ΔF508 mutation, which impairs CFTR folding, processing, function, and stability. Studies in homozygous ΔF508 CF patients indicated little clinical benefit of monotherapy with the investigational corrector VX-809 (lumacaftor) or VX-770, whereas combination clinical trials show limited but significant improvements in lung function. We show that VX-770, as well as most other potentiators, reduces the correction efficacy of VX-809 and another investigational corrector, VX-661. To mimic the administration of VX-770 alone or in combination with VX-809, we examined its long-term effect in immortalized and primary human respiratory epithelia. VX-770 diminished the folding efficiency and the metabolic stability of ΔF508-CFTR at the endoplasmic reticulum (ER) and post-ER compartments, respectively, causing reduced cell surface ΔF508-CFTR density and function. VX-770-induced destabilization of ΔF508-CFTR was influenced by second-site suppressor mutations of the folding defect and was prevented by stabilization of the nucleotide-binding domain 1 (NBD1)-NBD2 interface. The reduced correction efficiency of ΔF508-CFTR, as well as of two other processing mutations in the presence of VX-770, suggests the need for further optimization of potentiators to maximize the clinical benefit of corrector-potentiator combination therapy in CF.
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Affiliation(s)
- Guido Veit
- Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Radu G Avramescu
- Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Doranda Perdomo
- Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Puay-Wah Phuan
- Departments of Medicine and Physiology, University of California, San Francisco, San Francisco, CA 94143-0521, USA
| | - Miklos Bagdany
- Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Pirjo M Apaja
- Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Florence Borot
- Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Daniel Szollosi
- MTA-SE Molecular Biophysics Research Group, Hungarian Academy of Sciences, 1444 Budapest, Hungary. Department of Biophysics and Radiation Biology, Semmelweis University, 1444 Budapest P.O. Box 263, Hungary
| | - Yu-Sheng Wu
- Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Walter E Finkbeiner
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143-0511, USA
| | - Tamas Hegedus
- MTA-SE Molecular Biophysics Research Group, Hungarian Academy of Sciences, 1444 Budapest, Hungary. Department of Biophysics and Radiation Biology, Semmelweis University, 1444 Budapest P.O. Box 263, Hungary
| | - Alan S Verkman
- Departments of Medicine and Physiology, University of California, San Francisco, San Francisco, CA 94143-0521, USA
| | - Gergely L Lukacs
- Department of Physiology, McGill University, Montréal, Quebec H3G 1Y6, Canada. Department of Biochemistry, McGill University, Montréal, Quebec H3G 1Y6, Canada. Groupe de Recherche Axé sur la Structure des Protéines (GRASP), McGill University, Montréal, Quebec H3G 1Y6, Canada.
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20
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de Vries L, Griffiths A, Armstrong D, Robinson PJ. Cytokine gene polymorphisms and severity of CF lung disease. J Cyst Fibros 2014; 13:699-705. [DOI: 10.1016/j.jcf.2014.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 04/23/2014] [Accepted: 04/24/2014] [Indexed: 01/25/2023]
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21
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Bagheri-Hanson A, Nedwed S, Rueckes-Nilges C, Naehrlich L. Intestinal current measurement versus nasal potential difference measurements for diagnosis of cystic fibrosis: a case-control study. BMC Pulm Med 2014; 14:156. [PMID: 25280757 PMCID: PMC4199064 DOI: 10.1186/1471-2466-14-156] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 09/29/2014] [Indexed: 12/16/2022] Open
Abstract
Background Nasal potential difference (NPD) and intestinal current measurement (ICM) are functional CFTR tests that are used as adjunctive diagnostic tools for cystic fibrosis (CF). Smoking has a systemic negative impact on CFTR function. A diagnostic comparison between NPD and ICM and the impact of smoking on both CFTR tests has not been done. Methods The sweat chloride test, NPD, and ICM were performed in 18 patients with CF (sweat chloride >60 mmol/l), including 6 pancreatic sufficient (PS) patients, and 13 healthy controls, including 8 smokers. The NPD CFTR response to Cl-free and isoproterenol perfusion (Δ0Cl- + Iso) was compared to the ICM CFTR response to forskolin/IBMX, carbachol, and histamine (ΔIsc, forskolin/IBMX+ carbachol+histamine). Results The mean NPD CFTR response and ICM CFTR response between patients with CF and healthy controls was significantly different (p <0.001), but not between patients with CF who were PS and those who were pancreatic insufficient (PI). Smokers have a decreased CFTR response measured by NPD (p = 0.049). For ICM there is a trend towards decreased CFTR response (NS). Three healthy control smokers had NPD responses within the CF-range. In contrast to NPD, there was no overlap of the ICM response between patients with CF and controls. Conclusions ICM is superior to NPD in distinguishing between patients with CF who have a sweat chloride > 60 mmol/l and healthy controls, including smokers. Neither NPD nor ICM differentiated between patients with CF who were PS from those who were PI. Smoking has a negative impact on CFTR function in healthy controls measured by NPD and challenges the diagnostic interpretation of NPD, but not ICM. Electronic supplementary material The online version of this article (doi:10.1186/1471-2466-14-156) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | - Lutz Naehrlich
- Department of Pediatrics, Justus-Liebig-University Giessen, Feulgenstrasse 12, 35385 Giessen, Germany.
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22
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Tümmler B. The stony road to phe508del CFTR pharmacotherapy: smoothing the first rock. THE LANCET RESPIRATORY MEDICINE 2014; 2:508-9. [PMID: 24973279 DOI: 10.1016/s2213-2600(14)70136-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Burkhard Tümmler
- Clinic for Paediatric Pneumology, Allergology, and Neonatology, OE 6710, Hanover Medical School, D-30625 Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Centre for Lung Research, Hannover, Germany.
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Guillot L, Beucher J, Tabary O, Le Rouzic P, Clement A, Corvol H. Lung disease modifier genes in cystic fibrosis. Int J Biochem Cell Biol 2014; 52:83-93. [PMID: 24569122 DOI: 10.1016/j.biocel.2014.02.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/12/2014] [Accepted: 02/14/2014] [Indexed: 11/30/2022]
Abstract
Cystic fibrosis (CF) is recognized as a single gene disorder. However, a considerable diversity in its clinical phenotype has been documented since the description of the disease. Identification of additional gene alleles, so called "modifier genes" that directly influence the phenotype of CF disease became a challenge in the late '90ies, not only for the insight it provides into the CF pathophysiology, but also for the development of new potential therapeutic targets. One of the most studied phenotype has been the lung disease severity as lung dysfunction is the major cause of morbidity and mortality in CF. This review details the results of two main genetic approaches that have mainly been explored so far: (1) an "a priori" approach, i.e. the candidate gene approach; (2) a "without a priori" approach, analyzing the whole genome by linkage and genome-wide association studies (GWAS), or the whole exome by exome sequencing.
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Affiliation(s)
- Loic Guillot
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France.
| | - Julie Beucher
- Centre Hospiyalo-Universitaire (CHU), Rennes, France
| | - Olivier Tabary
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France
| | - Philippe Le Rouzic
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France
| | - Annick Clement
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France; Hôpital Trousseau, Pediatric Respiratory Department, AP-HP, Paris, France
| | - Harriet Corvol
- INSERM, UMR_S 938, CDR Saint-Antonie , Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_s 938, CDR Saint-Antonie, Paris, France; Hôpital Trousseau, Pediatric Respiratory Department, AP-HP, Paris, France
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Abstract
Proteomics was initially viewed as a promising new scientific discipline to study complex disorders such as polygenic, infectious and environment-related diseases. However, the first attempts to understand a monogenic disease such as cystic fibrosis (CF) by proteomics-based approaches have proved quite rewarding. In CF, the impairment of a unique protein, the CF transmembrane conductance regulator, does not completely explain the complex and variable CF clinical phenotype. The great advances in our knowledge about the molecular and cellular consequences of such impairment have not been sufficient to be translated into effective treatments, and CF patients are still dying due to chronic progressive lung dysfunction. The progression of proteomics application in CF will certainly unravel new proteins that could be useful as biomarkers either to elucidate CF basic mechanisms and to better monitor the disease progression, or to promote the development of novel therapeutic strategies against CF. This review will summarize the recent technological advances in proteomics and the first results of its application to address the most important issues in the CF field.
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Affiliation(s)
- Deborah Penque
- Instituto Nacional de Saúde Dr Ricardo Jorge, Laboratório de Proteómica, Centro de Genética Humana, Lisboa, Portugal.
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Song MH, Shin JW, Park HJ, Lee KA, Kim Y, Kim UK, Jeon JH, Choi JY. Intrafamilial phenotypic variability in families with biallelic SLC26A4 mutations. Laryngoscope 2013; 124:E194-202. [PMID: 24338212 DOI: 10.1002/lary.24504] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 09/26/2013] [Accepted: 10/30/2013] [Indexed: 11/05/2022]
Abstract
OBJECTIVES/HYPOTHESIS Enlarged vestibular aqueduct (EVA) and hearing loss are known to be caused by SLC26A4 mutations, but large phenotypic variability exists among patients with biallelic SLC26A4 mutations. Intrafamilial phenotypic variability was analyzed in multiplex EVA families carrying biallelic SLC26A4 mutations to identify the contribution of SLC26A4 mutations and other genetic or environmental factors influencing the clinical manifestations. STUDY DESIGN Retrospective case series. METHODS Eleven multiplex Korean families with EVA and hearing loss that carry biallelic mutations of the SLC26A4 gene were included. Genetic analysis for SLC26A4 and other genes including FOXI1, FOXI1-DBD, and KCNJ10 was performed. The auditory and other phenotypes were compared among siblings with the same SLC26A4 mutations. RESULTS The difference in the auditory phenotypes was identified between siblings in approximately half of the EVA families. Families with SLC26A4 mutations other than H723R homozygous mutations demonstrated more phenotypic variability, especially in those carrying IVS7-2A>G splice site mutation. Cochlear malformation was a consistent finding among siblings with the same SLC26A4 mutations. No mutation was identified in the FOXI1, FOXI1-DBD, and KCNJ10 genes in the tested families. CONCLUSIONS The possibility of variability concerning auditory phenotype should be considered even within family members carrying the same SLC26A4 mutations when providing genetic counseling to multiplex EVA families. Mutations in the currently known genes associated with EVA other than SLC26A4 were not found to be responsible for the intrafamilial phenotypic variability. Modifier genes or environmental factors other than the currently known genes seem to play a role in the phenotypic expressions of EVA patients.
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Affiliation(s)
- Mee Hyun Song
- Department of Otorhinolaryngology, Kwandong University College of Medicine, Myongji Hospital, Goyang, South Korea
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Wine JJ, Char JE, Chen J, Cho HJ, Dunn C, Frisbee E, Joo NS, Milla C, Modlin SE, Park IH, Thomas EAC, Tran KV, Verma R, Wolfe MH. In vivo readout of CFTR function: ratiometric measurement of CFTR-dependent secretion by individual, identifiable human sweat glands. PLoS One 2013; 8:e77114. [PMID: 24204751 PMCID: PMC3811985 DOI: 10.1371/journal.pone.0077114] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 08/29/2013] [Indexed: 12/14/2022] Open
Abstract
To assess CFTR function in vivo, we developed a bioassay that monitors and compares CFTR-dependent and CFTR-independent sweat secretion in parallel for multiple (~50) individual, identified glands in each subject. Sweating was stimulated by intradermally injected agonists and quantified by optically measuring spherical sweat bubbles in an oil-layer that contained dispersed, water soluble dye particles that partitioned into the sweat bubbles, making them highly visible. CFTR-independent secretion (M-sweat) was stimulated with methacholine, which binds to muscarinic receptors and elevates cytosolic calcium. CFTR-dependent secretion (C-sweat) was stimulated with a β-adrenergic cocktail that elevates cytosolic cAMP while blocking muscarinic receptors. A C-sweat/M-sweat ratio was determined on a gland-by-gland basis to compensate for differences unrelated to CFTR function, such as gland size. The average ratio provides an approximately linear readout of CFTR function: the heterozygote ratio is ~0.5 the control ratio and for CF subjects the ratio is zero. During assay development, we measured C/M ratios in 6 healthy controls, 4 CF heterozygotes, 18 CF subjects and 4 subjects with 'CFTR-related' conditions. The assay discriminated all groups clearly. It also revealed consistent differences in the C/M ratio among subjects within groups. We hypothesize that these differences reflect, at least in part, levels of CFTR expression, which are known to vary widely. When C-sweat rates become very low the C/M ratio also tended to decrease; we hypothesize that this nonlinearity reflects ductal fluid absorption. We also discovered that M-sweating potentiates the subsequent C-sweat response. We then used potentiation as a surrogate for drugs that can increase CFTR-dependent secretion. This bioassay provides an additional method for assessing CFTR function in vivo, and is well suited for within-subject tests of systemic, CFTR-directed therapeutics.
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Affiliation(s)
- Jeffrey J. Wine
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Psychology, Stanford University, Stanford, California, United States of America
| | - Jessica E. Char
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Jonathan Chen
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Hyung-ju Cho
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Colleen Dunn
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Eric Frisbee
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Nam Soo Joo
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Carlos Milla
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Sara E. Modlin
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Il-Ho Park
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Ewart A. C. Thomas
- Department of Psychology, Stanford University, Stanford, California, United States of America
| | - Kim V. Tran
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Rohan Verma
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Marlene H. Wolfe
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
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Vanakker OM, Hosen MJ, Paepe AD. The ABCC6 transporter: what lessons can be learnt from other ATP-binding cassette transporters? Front Genet 2013; 4:203. [PMID: 24137173 PMCID: PMC3797522 DOI: 10.3389/fgene.2013.00203] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 09/23/2013] [Indexed: 01/31/2023] Open
Abstract
ABC transporters represent a large family of ATP-driven transmembrane transporters involved in uni- or bidirectional transfer of a large variety of substrates. Divided in seven families, they represent 48 transporter proteins, several of which have been associated with human disease. Among the latter is ABCC6, a unidirectional exporter protein primarily expressed in liver and kidney. ABCC6 deficiency has been shown to cause the ectopic mineralization disorder pseudoxanthoma elasticum (PXE), characterized by calcification and fragmentation of elastic fibers, resulting in oculocutaneous and cardiovascular symptoms. Unique in the group of connective tissue disorders, the pathophysiological relation between the ABCC6 transporter and ectopic mineralization in PXE remains enigmatic, not in the least because of lack of knowledge on the substrate(s) of ABCC6 and its unusual expression pattern. Because many features, including structure and transport mechanism, are shared by many ABC transporters, it is worthwhile to evaluate if and to what extent the knowledge on the physiology and pathophysiology of these other transporters may provide useful clues toward understanding the (patho)physiological role of ABCC6 and how its deficiency may be dealt with.
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Stanke F, van Barneveld A, Hedtfeld S, Wölfl S, Becker T, Tümmler B. The CF-modifying gene EHF promotes p.Phe508del-CFTR residual function by altering protein glycosylation and trafficking in epithelial cells. Eur J Hum Genet 2013; 22:660-6. [PMID: 24105369 PMCID: PMC3992571 DOI: 10.1038/ejhg.2013.209] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/26/2013] [Accepted: 08/09/2013] [Indexed: 01/07/2023] Open
Abstract
The three-base-pair deletion c.1521_1523delCTT (p.Phe508del, F508del) in the cystic fibrosis transmembrane conductance regulator (CFTR) is the most frequent disease-causing lesion in cystic fibrosis (CF). The CFTR gene encodes a chloride and bicarbonate channel at the apical membrane of epithelial cells. Altered ion transport of CFTR-expressing epithelia can be used to differentiate manifestations of the so-called CF basic defect. Recently, an 11p13 region has been described as a CF modifier by the North American CF Genetic Modifier Study Consortium. Selecting the epithelial-specific transcription factor EHF (ets homologous factor) as the likely candidate gene on 11p13, we have genotyped two intragenic microsatellites in EHF to replicate the 11p13 finding in the patient cohort of the European CF Twin and Sibling Study. We could observe an association of rare EHF haplotypes among homozygotes for c.1521_1523delCTT in CFTR, which exhibit a CF-untypical manifestation of the CF basic defect such as CFTR-mediated residual chloride secretion and low response to amiloride. We have reviewed transcriptome data obtained from intestinal epithelial samples of homozygotes for c.1521_1523delCTT in CFTR, which were stratified for their EHF genetic background. Transcripts that were upregulated among homozygotes for c.1521_1523delCTT in CFTR, who carry two rare EHF alleles, were enriched for genes that alter protein glycosylation and trafficking, both mechanisms being pivotal for the effective targeting of fully functional p.Phe508del-CFTR to the apical membrane of epithelial cells. We conclude that EHF modifies the CF phenotype by altering capabilities of the epithelial cell to correctly process the folding and trafficking of mutant p.Phe508del-CFTR.
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Affiliation(s)
- Frauke Stanke
- 1] Department of Pediatrics, Hannover Medical School, Hannover, Germany [2] Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Germany
| | - Andrea van Barneveld
- 1] Department of Pediatrics, Hannover Medical School, Hannover, Germany [2] Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Germany
| | - Silke Hedtfeld
- 1] Department of Pediatrics, Hannover Medical School, Hannover, Germany [2] Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Germany
| | - Stefan Wölfl
- Institute for Pharmacy and Molecular Biotechnology, Ruperto-Carola University of Heidelberg, Heidelberg, Germany
| | - Tim Becker
- 1] German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany [2] Institute of Medical Biometry, Informatics and Epidemiology, University of Bonn, Bonn, Germany
| | - Burkhard Tümmler
- 1] Department of Pediatrics, Hannover Medical School, Hannover, Germany [2] Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Germany
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Lee H, Jung J, Shin J, Song M, Kim S, Lee JH, Lee KA, Shin S, Kim UK, Bok J, Lee KY, Choi J, Park H. Correlation between genotype and phenotype in patients with bi-allelicSLC26A4mutations. Clin Genet 2013; 86:270-5. [DOI: 10.1111/cge.12273] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 09/03/2013] [Accepted: 09/03/2013] [Indexed: 11/27/2022]
Affiliation(s)
- H.J. Lee
- Department of Otorhinolaryngology
- BK21 Project for Medical Science
| | - J. Jung
- Department of Pharmacology; Yonsei University College of Medicine; Seoul Republic of Korea
- BK21 Project for Medical Science
| | - J.W. Shin
- Department of Otorhinolaryngology
- Soree Ear Clinics; Seoul Republic of Korea
| | | | - S.H. Kim
- Department of Otorhinolaryngology
| | - J.-H. Lee
- Department of Pharmacology; Yonsei University College of Medicine; Seoul Republic of Korea
| | - K.-A. Lee
- Department of Laboratory Medicine; Yonsei University College of Medicine; Seoul Republic of Korea
| | - S. Shin
- Department of Laboratory Medicine; Yonsei University College of Medicine; Seoul Republic of Korea
| | - U.-K. Kim
- Department of Biology, College of Natural Sciences; Kyungpook National University; Daegu Republic of Korea
| | - J. Bok
- Department of Anatomy; Yonsei University College of Medicine; Seoul Republic of Korea
| | - K.-Y. Lee
- Department of Otorhinolaryngology; Kyungpook National University; Daegu Republic of Korea
| | - J.Y. Choi
- Department of Otorhinolaryngology
- BK21 Project for Medical Science
| | - H.J. Park
- Soree Ear Clinics; Seoul Republic of Korea
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Multicenter intestinal current measurements in rectal biopsies from CF and non-CF subjects to monitor CFTR function. PLoS One 2013; 8:e73905. [PMID: 24040112 PMCID: PMC3769519 DOI: 10.1371/journal.pone.0073905] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 07/23/2013] [Indexed: 11/30/2022] Open
Abstract
Intestinal current measurements (ICM) from rectal biopsies are a sensitive means to detect cystic fibrosis transmembrane conductance regulator (CFTR) function, but have not been optimized for multicenter use. We piloted multicenter standard operating procedures (SOPs) to detect CFTR activity by ICM and examined key questions for use in clinical trials. SOPs for ICM using human rectal biopsies were developed across three centers and used to characterize ion transport from non-CF and CF subjects (two severe CFTR mutations). All data were centrally evaluated by a blinded interpreter. SOPs were then used across four centers to examine the effect of cold storage on CFTR currents and compare CFTR currents in biopsies from one subject studied simultaneously either at two sites (24 hours post-biopsy) or when biopsies were obtained by either forceps or suction. Rectal biopsies from 44 non-CF and 17 CF subjects were analyzed. Mean differences (µA/cm2; 95% confidence intervals) between CF and non-CF were forskolin/IBMX=102.6(128.0 to 81.1), carbachol=96.3(118.7 to 73.9), forskolin/IBMX+carbachol=200.9(243.1 to 158.6), and bumetanide=-44.6 (-33.7 to -55.6) (P<0.005, CF vs non-CF for all parameters). Receiver Operating Characteristic curves indicated that each parameter discriminated CF from non-CF subjects (area under the curve of 0.94-0.98). CFTR dependent currents following 18-24 hours of cold storage for forskolin/IBMX, carbachol, and forskolin/IBMX+carbachol stimulation (n=17 non-CF subjects) were 44%, 47.5%, and 47.3%, respectively of those in fresh biopsies. CFTR-dependent currents from biopsies studied after cold storage at two sites simultaneously demonstrated moderate correlation (n=14 non-CF subjects, Pearson correlation coefficients 0.389, 0.484, and 0.533). Similar CFTR dependent currents were detected from fresh biopsies obtained by either forceps or suction (within-subject comparisons, n=22 biopsies from three non-CF subjects). Multicenter ICM is a feasible CFTR outcome measure that discriminates CF from non-CF ion transport, offers unique advantages over other CFTR bioassays, and warrants further development as a potential CFTR biomarker.
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31
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van Meegen MA, Terheggen-Lagro SWJ, Koymans KJ, van der Ent CK, Beekman JM. Apical CFTR expression in human nasal epithelium correlates with lung disease in cystic fibrosis. PLoS One 2013; 8:e57617. [PMID: 23483918 PMCID: PMC3590182 DOI: 10.1371/journal.pone.0057617] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Accepted: 01/24/2013] [Indexed: 02/06/2023] Open
Abstract
Introduction Although most individuals with cystic fibrosis (CF) develop progressive obstructive lung disease, disease severity is highly variable, even for individuals with similar CFTR mutations. Measurements of chloride transport as expression of CFTR function in nasal epithelial cells correlate with pulmonary function and suggest that F508del-CFTR is expressed at the apical membrane. However, an association between quantitative apical CFTR expression in nasal epithelium and CF disease severity is still missing. Methods and Materials Nasal epithelial cells from healthy individuals and individuals with CF between 12–18 years were obtained by nasal brushing. Apical CFTR expression was measured by confocal microscopy using CFTR mAb 596. Expression was compared between both groups and expression in CF nasal epithelial cells was associated with standardized pulmonary function (FEV1%). Results The proportion of cells expressing apical CFTR in columnar epithelium is lower in CF compared to non-CF. The apical CFTR expression level was significantly correlated with FEV1% in F508del homozygous subjects (r = 0.63, p = 0.012). Conclusion CFTR expression in nasal epithelial cells is lower in subjects with CF compared to healthy subjects. The proportion of cells expressing F508del-CFTR at the apical membrane is variable between subjects and is positively correlated with FEV1% in F508del-CFTR homozygous subjects.
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Affiliation(s)
- Marit Arianne van Meegen
- Department of Pediatric Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands
- Centre for Molecular and Cellular Intervention, University Medical Center Utrecht, Utrecht, The Netherlands
- Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Kirsten Judith Koymans
- Department of Pediatric Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands
- Centre for Molecular and Cellular Intervention, University Medical Center Utrecht, Utrecht, The Netherlands
- Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Jeffrey Matthijn Beekman
- Department of Pediatric Pulmonology, University Medical Center Utrecht, Utrecht, The Netherlands
- Centre for Molecular and Cellular Intervention, University Medical Center Utrecht, Utrecht, The Netherlands
- Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
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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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Flume PA, Liou TG, Borowitz DS, Li H, Yen K, Ordoñez CL, Geller DE. Ivacaftor in subjects with cystic fibrosis who are homozygous for the F508del-CFTR mutation. Chest 2013; 142:718-724. [PMID: 22383668 DOI: 10.1378/chest.11-2672] [Citation(s) in RCA: 226] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Ivacaftor (VX-770) is a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator that was approved in the United States for the treatment of cystic fibrosis (CF) in patients ≥ 6 years of age who have a G551D mutation; however, the most prevalent disease-causing CFTR mutation, F508del, causes a different functional defect. The objectives of this study were to evaluate the safety of ivacaftor in a larger population and for a longer time period than tested previously and to assess the efficacy of ivacaftor in subjects with CF who are homozygous for F508del-CFTR. METHODS This was a phase 2 study with a 16-week randomized (4:1), double-blind, placebo-controlled period (part A) and an open-label extension (part B) for subjects who met prespecified criteria. RESULTS Part A: The safety profile of ivacaftor was comparable to that of the placebo. The overall adverse event frequency was similar in the ivacaftor (87.5%) and placebo (89.3%) groups through 16 weeks. The difference in the change of FEV₁ % predicted from baseline through week 16 (primary end point) between the ivacaftor and placebo groups was 1.7% (P = .15). Sweat chloride, a biomarker of CFTR activity, showed a small reduction in the ivacaftor vs placebo groups of -2.9 mmol/L (P = .04) from baseline through week 16. Part B: No new safety signals were identified. The changes in FEV₁ or sweat chloride in part A were not sustained with ivacaftor treatment from week 16 to week 40. CONCLUSIONS These results expand the safety information for ivacaftor and support its continued evaluation. Lack of a clinical effect suggests that a CFTR potentiator alone is not an effective therapeutic approach for patients who have CF and are homozygous for F508del-CFTR. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT00953706; URL: www.clinicaltrials.gov.
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Affiliation(s)
- Patrick A Flume
- Department of Medicine and Pediatrics, Medical University of South Carolina, Charleston, SC.
| | | | - Drucy S Borowitz
- Department of Pediatrics, State University of New York at Buffalo, Buffalo, NY
| | - Haihong Li
- Vertex Pharmaceuticals Incorporated, Cambridge, MA
| | - Karl Yen
- Vertex Pharmaceuticals Incorporated, Cambridge, MA
| | | | - David E Geller
- Divisions of Biomedical Research and Pediatric Pulmonology, Nemours Children's Clinic, Orlando, FL
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Wilke M, Bot A, Jorna H, Scholte BJ, de Jonge HR. Rescue of murine F508del CFTR activity in native intestine by low temperature and proteasome inhibitors. PLoS One 2012; 7:e52070. [PMID: 23284872 PMCID: PMC3528711 DOI: 10.1371/journal.pone.0052070] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 11/15/2012] [Indexed: 11/19/2022] Open
Abstract
Most patients with Cystic Fibrosis (CF) carry at least one allele with the F508del mutation, resulting in a CFTR chloride channel protein with a processing, gating and stability defect, but with substantial residual activity when correctly sorted to the apical membranes of epithelial cells. New therapies are therefore aimed at improving the folding and trafficking of F508del CFTR, (CFTR correctors) or at enhancing the open probability of the CFTR chloride channel (CFTR potentiators). Preventing premature breakdown of F508del CFTR is an alternative or additional strategy, which is investigated in this study. We established an ex vivo assay for murine F508del CFTR rescue in native intestinal epithelium that can be used as a pre-clinical test for candidate therapeutics. Overnight incubation of muscle stripped ileum in modified William's E medium at low temperature (26°C), and 4 h or 6 h incubation at 37°C with different proteasome inhibitors (PI: ALLN, MG-132, epoxomicin, PS341/bortezomib) resulted in fifty to hundred percent respectively of the wild type CFTR mediated chloride secretion (forskolin induced short-circuit current). The functional rescue was accompanied by enhanced expression of the murine F508del CFTR protein at the apical surface of intestinal crypts and a gain in the amount of complex-glycosylated CFTR (band C) up to 20% of WT levels. Sustained rescue in the presence of brefeldin A shows the involvement of a post-Golgi compartment in murine F508del CFTR degradation, as was shown earlier for its human counterpart. Our data show that proteasome inhibitors are promising candidate compounds for improving rescue of human F508del CFTR function, in combination with available correctors and potentiators.
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Affiliation(s)
- Martina Wilke
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands.
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Kolbe EW, Tamm S, Hedtfeld S, Becker T, Tümmler B, Stanke F. CLCA4 variants determine the manifestation of the cystic fibrosis basic defect in the intestine. Eur J Hum Genet 2012; 21:691-4. [PMID: 23073314 PMCID: PMC3658199 DOI: 10.1038/ejhg.2012.234] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The manifestation of the monogenic disease cystic fibrosis results from the cystic fibrosis transmembrane conductance regulator (CFTR)-mediated basic defect defined as an altered chloride transport. An association study using contrasting endophenotypes was conducted with 17 markers to allow fine-mapping of a previously reported association signal within the CLCA gene cluster. Markers were analyzed for association with the manifestation of the basic defect in the patient population of the European CF Twin and Sibling Study composed of 101 families with a total of 171 patients. The manifestation of the basic defect was associated with markers rs11807298–rs6684219, encompassing the CLCA4 promoter (Praw=0.0013; Pcorr=0.0157). Refined analysis of the CLCA4 association signal among F508del homozygous CF patients who exhibit either no, CFTR-mediated or Ca2+-mediated residual chloride conductance revealed that allele distributions for markers rs11807298–rs113894048–rs6684219 differed significantly among these three patient groups. Our data strongly argue that CLCA4 modulates the capability to express residual chloride secretion in colonic tissue. The latter finding is in consistency with the now favored role of the CLCA proteins in signal transduction in epithelial cells.
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GUSTAFSSON JK, HANSSON GC, SJÖVALL H. Ulcerative colitis patients in remission have an altered secretory capacity in the proximal colon despite macroscopically normal mucosa. Neurogastroenterol Motil 2012; 24:e381-91. [PMID: 22726848 PMCID: PMC4871264 DOI: 10.1111/j.1365-2982.2012.01958.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND One of the hallmarks of acute colitis is loss of epithelial transport. For unknown reasons, many patients still suffer from GI symptoms during remission, indicating a sustained imbalance between absorption and secretion. We hypothesize that the colonic epithelium becomes more reactive to secretagogues to compensate for a failing barrier. METHODS Biopsies from ascending colon and sigmoid colon of UC patients in remission and controls were mounted in Ussing chambers. Membrane current (Im) and epithelial capacitance (Cp) were used as markers for anion secretion and mucus exocytosis. Carbachol (1 mmol L(-1) ) and forskolin (10 μmol L(-1) ) were used to study Ca(2+) and cAMP-mediated secretion. KEY RESULTS Baseline values showed segmental patterns with higher Im in ascending colon and higher Cp in sigmoid colon of both UC patients and controls, but the patterns did not differ between the groups. The Im response to forskolin was increased (+35%) in the ascending colon of UC patients and the Im response to carbachol was decreased (-40%) in the same segment. No group differences were seen in the distal colon for either the forskolin or carbachol-induced Im responses. The Cp response to carbachol was instead up-regulated in the distal colon of UC patients, but remained unaffected in the proximal colon. CONCLUSIONS & INFERENCES The proximal colonic mucosa of UC patients in remission seems to shift its reactivity to secretagogues, becoming more sensitive to cAMP-dependent secretion and less sensitive to Ca(2+) -dependent secretion. This phenomenon may contribute to residual diarrhea in this patient group, despite resolution of inflammation.
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Affiliation(s)
- J. K. GUSTAFSSON
- Department of Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden,Department of Medical Biochemistry and Cell Biology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - G. C. HANSSON
- Department of Medical Biochemistry and Cell Biology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - H. SJÖVALL
- Department of Internal Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Burney TJ, Davies JC. Gene therapy for the treatment of cystic fibrosis. APPLICATION OF CLINICAL GENETICS 2012; 5:29-36. [PMID: 23776378 PMCID: PMC3681190 DOI: 10.2147/tacg.s8873] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Gene therapy is being developed as a novel treatment for cystic fibrosis (CF), a condition that has hitherto been widely-researched yet for which no treatment exists that halts the progression of lung disease. Gene therapy involves the transfer of correct copies of cystic fibrosis transmembrane conductance regulator (CFTR) DNA to the epithelial cells in the airways. The cloning of the CFTR gene in 1989 led to proof-of-principle studies of CFTR gene transfer in vitro and in animal models. The earliest clinical trials in CF patients were conducted in 1993 and used viral and non-viral gene transfer agents in both the nasal and bronchial airway epithelium. To date, studies have focused largely on molecular or bioelectric (chloride secretion) outcome measures, many demonstrating evidence of CFTR expression, but few have attempted to achieve clinical efficacy. As CF is a lifelong disease, turnover of the airway epithelium necessitates repeat administration. To date, this has been difficult to achieve with viral gene transfer agents due to host recognition leading to loss of expression. The UK Cystic Fibrosis Gene Therapy Consortium (Imperial College London, University of Edinburgh and University of Oxford) is currently working on a large and ambitious program to establish the clinical benefits of CF gene therapy. Wave 1, which has reached the clinic, uses a non-viral vector. A single-dose safety trial is nearing completion and a multi-dose clinical trial is shortly due to start; this will be powered for clinically-relevant changes. Wave 2, more futuristically, will look at the potential of lentiviruses, which have long-lasting expression. This review will summarize the current status of translational research in CF gene therapy.
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Affiliation(s)
- Tabinda J Burney
- Department of Gene Therapy, Imperial College London ; UK CF Gene Therapy Consortium London
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Labenski H, Hedtfeld S, Becker T, Tümmler B, Stanke F. Initial interrogation, confirmation and fine mapping of modifying genes: STAT3, IL1B and IFNGR1 determine cystic fibrosis disease manifestation. Eur J Hum Genet 2011; 19:1281-8. [PMID: 21731057 PMCID: PMC3230365 DOI: 10.1038/ejhg.2011.129] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 03/24/2011] [Accepted: 05/24/2011] [Indexed: 02/08/2023] Open
Abstract
We have used a stepwise approach consisting of initial interrogation, confirmation and fine mapping to analyze STAT3, IL1B and IFNGR1 as modifiers of cystic fibrosis disease building upon the data and sample collection of the European Cystic Fibrosis Twin and Sibling Study. We have observed direct correlation between the length of the intronic microsatellite STAT3Sat to STAT3 expression levels among F508del-CFTR homozygous patients (P=0.0075), and an association of longer STAT3Sat-alleles with the presence of CFTR-mediated residual chloride secretion (P=0.0031), measured as the manifestation of the CF basic defect in intestinal tissue. Both, family-based analysis by TDT and case-reference comparison identified consistently the same intragenic IL1B haplotype as a risk variant (P(raw)=0.055 for TDT, P(raw)<0.3 for case-reference comparison). Using haplotype-guided hierarchical fine mapping, we have identified two single nucleotide exchanges for which concordant and discordant sibling pairs differ at a 7 kb-spanning core haplotype in IFNGR1 (P(raw)=0.0113). Taken together, our findings imply that immunorelevant pathways and ion secretion, dominated by CFTR in intestinal and respiratory epithelium, merge at the level of the epithelial cell to integrate the signaling of cytokines due to innate and acquired immune defense.
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Affiliation(s)
- Heike Labenski
- Department of Pediatrics, Hannover Medical School, Hannover, Germany
| | - Silke Hedtfeld
- Department of Pediatrics, Hannover Medical School, Hannover, Germany
| | - Tim Becker
- Institute of Medical Biometry, Informatics and Epidemiology, University of Bonn, Bonn, Germany
| | - Burkhard Tümmler
- Department of Pediatrics, Hannover Medical School, Hannover, Germany
| | - Frauke Stanke
- Department of Pediatrics, Hannover Medical School, Hannover, Germany
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Abstract
Several diseases have been clinically or genetically related to cystic fibrosis (CF), but a consensus definition is lacking. Here, we present a proposal for consensus guidelines on cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (CFTR-RDs), reached after expert discussion and two dedicated workshops. A CFTR-RD may be defined as "a clinical entity associated with CFTR dysfunction that does not fulfil diagnostic criteria for CF". The utility of sweat testing, mutation analysis, nasal potential difference, and/or intestinal current measurement for the differential diagnosis of CF and CFTR-RD is discussed. Algorithms which use genetic and functional diagnostic tests to distinguish CF and CFTR-RDs are presented. According to present knowledge, congenital bilateral absence of vas deferens (CBAVD), acute recurrent or chronic pancreatitis and disseminated bronchiectasis, all with CFTR dysfunction, are CFTR-RDs.
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40
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Clancy JP, Rowe SM, Accurso FJ, Aitken ML, Amin RS, Ashlock MA, Ballmann M, Boyle MP, Bronsveld I, Campbell PW, De Boeck K, Donaldson SH, Dorkin HL, Dunitz JM, Durie PR, Jain M, Leonard A, McCoy KS, Moss RB, Pilewski JM, Rosenbluth DB, Rubenstein RC, Schechter MS, Botfield M, Ordoñez CL, Spencer-Green GT, Vernillet L, Wisseh S, Yen K, Konstan MW. Results of a phase IIa study of VX-809, an investigational CFTR corrector compound, in subjects with cystic fibrosis homozygous for the F508del-CFTR mutation. Thorax 2011; 67:12-8. [PMID: 21825083 DOI: 10.1136/thoraxjnl-2011-200393] [Citation(s) in RCA: 416] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND VX-809, a cystic fibrosis transmembrane conductance regulator (CFTR) modulator, has been shown to increase the cell surface density of functional F508del-CFTR in vitro. METHODS A randomised, double-blind, placebo-controlled study evaluated the safety, tolerability and pharmacodynamics of VX-809 in adult patients with cystic fibrosis (n=89) who were homozygous for the F508del-CFTR mutation. Subjects were randomised to one of four VX-809 28 day dose groups (25, 50, 100 and 200 mg) or matching placebo. RESULTS The type and incidence of adverse events were similar among VX-809- and placebo-treated subjects. Respiratory events were the most commonly reported and led to discontinuation by one subject in each active treatment arm. Pharmacokinetic data supported a once-daily oral dosing regimen. Pharmacodynamic data suggested that VX-809 improved CFTR function in at least one organ (sweat gland). VX-809 reduced elevated sweat chloride values in a dose-dependent manner (p=0.0013) that was statistically significant in the 100 and 200 mg dose groups. There was no statistically significant improvement in CFTR function in the nasal epithelium as measured by nasal potential difference, nor were there statistically significant changes in lung function or patient-reported outcomes. No maturation of immature F508del-CFTR was detected in the subgroup that provided rectal biopsy specimens. CONCLUSIONS In this study, VX-809 had a similar adverse event profile to placebo for 28 days in F508del-CFTR homozygous patients, and demonstrated biological activity with positive impact on CFTR function in the sweat gland. Additional data are needed to determine how improvements detected in CFTR function secondary to VX-809 in the sweat gland relate to those measurable in the respiratory tract and to long-term measures of clinical benefit. CLINICAL TRIAL NUMBER NCT00865904.
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Affiliation(s)
- J P Clancy
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
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Pyle LC, Ehrhardt A, Mitchell LH, Fan L, Ren A, Naren AP, Li Y, Clancy JP, Bolger GB, Sorscher EJ, Rowe SM. Regulatory domain phosphorylation to distinguish the mechanistic basis underlying acute CFTR modulators. Am J Physiol Lung Cell Mol Physiol 2011; 301:L587-97. [PMID: 21724857 DOI: 10.1152/ajplung.00465.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Modulator compounds intended to overcome disease-causing mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) show significant promise in clinical testing for cystic fibrosis. However, the mechanism(s) of action underlying these compounds are not fully understood. Activation of CFTR ion transport requires PKA-regulated phosphorylation of the regulatory domain (R-D) and dimerization of the nucleotide binding domains. Using a newly developed assay, we evaluated nine compounds including both CFTR potentatiators and activators discovered via various high-throughput screening strategies to acutely augment CFTR activity. We found considerable differences in the effects on R-D phosphorylation. Some (including UC(CF)-152) stimulated robust phosphorylation, and others had little effect (e.g., VRT-532 and VX-770). We then compared CFTR activation by UC(CF)-152 and VRT-532 in Ussing chamber studies using two epithelial models, CFBE41o(-) and Fischer rat thyroid cells, expressing various CFTR forms. UC(CF)-152 activated wild-type-, G551D-, and rescued F508del-CFTR currents but did not potentiate cAMP-mediated CFTR activation. In contrast, VRT-532 moderately activated CFTR short-circuit current and strongly potentiated forskolin-mediated current. Combined with the result that UC(CF)-152, but not VRT-532 or VX-770, acts by increasing CFTR R-D phosphorylation, these findings indicate that potentiation of endogenous cAMP-mediated activation of mutant CFTR is not due to a pathway involving augmented R-D phosphorylation. This study presents an assay useful to distinguish preclinical compounds by a crucial mechanism underlying CFTR activation, delineates two types of compound able to acutely augment CFTR activity (e.g., activators and potentiators), and demonstrates that a number of different mechanisms can be successfully employed to activate mutant CFTR.
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Affiliation(s)
- Louise C Pyle
- Departments of Genetics, University of Alabama at Birmingham, 35294-0006, USA
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De Boeck K, Derichs N, Fajac I, de Jonge H, Bronsveld I, Sermet I, Vermeulen F, Sheppard D, Cuppens H, Hug M, Melotti P, Middleton P, Wilschanski M. New clinical diagnostic procedures for cystic fibrosis in Europe. J Cyst Fibros 2011; 10 Suppl 2:S53-66. [DOI: 10.1016/s1569-1993(11)60009-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Stanke F, Hedtfeld S, Becker T, Tümmler B. An association study on contrasting cystic fibrosis endophenotypes recognizes KRT8 but not KRT18 as a modifier of cystic fibrosis disease severity and CFTR mediated residual chloride secretion. BMC MEDICAL GENETICS 2011; 12:62. [PMID: 21548936 PMCID: PMC3107781 DOI: 10.1186/1471-2350-12-62] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 05/06/2011] [Indexed: 12/23/2022]
Abstract
Background F508del-CFTR, the most frequent disease-causing mutation among Caucasian cystic fibrosis (CF) patients, has been characterised as a mutant defective in protein folding, processing and trafficking. We have investigated the two neighbouring cytokeratin genes KRT8 and KRT18 in a candidate gene approach to ask whether variants in KRT8 and/or KRT18 modify the impaired ion conductance known as the CF basic defect, and whether they are associated with correct trafficking of mutant CFTR and disease severity of CF. Methods We have selected contrasting F508del-CFTR homozygous patient subpopulations stratified for disease severity, comparing 13 concordant mildly affected sib pairs vs. 12 concordant severely affected sib pairs, or manifestation of the CF basic defect in intestinal epithelium, comparing 22 individuals who exhibit CFTR-mediated residual chloride secretion vs. 14 individuals who do not express any chloride secretion, for an association. The KRT8/KRT18 locus was initially interrogated with one informative microsatellite marker. Subsequently, a low density SNP map with four SNPs in KRT8 and two SNPs in KRT18, each selected for high polymorphism content, was used to localize the association signal. Results KRT8, but not KRT18, showed an association with CF disease severity (Pbest = 0.00131; Pcorr = 0.0185) and CFTR mediated residual chloride secretion (Pbest = 0.0004; Pcorr = 0.0069). Two major four-marker-haplotypes spanning 13 kb including the entire KRT8 gene accounted for 90% of chromosomes, demonstrating strong linkage disequilibrium at that locus. Absence of chloride secretion was associated with the recessive haplotype 1122 at rs1907671, rs4300473, rs2035878 and rs2035875. The contrasting haplotype 2211 was dominant for the presence of CFTR mediated residual chloride secretion. In consistency, the KRT8 haplotype 2211 was associated with mild CF disease while 1122 was observed as risk haplotype. Analysis of microsatellite allele distributions on the SNP background suggests that the mild KRT8 haplotype 2211 is phylogenetically older than its severe counterpart. Conclusions The two opposing KRT8 alleles which have been identified as a benign and as a risk allele in this work are likely effective in the context of epithelial cell differentiation. As the mild KRT8 allele is associated with CFTR mediated residual chloride secretion among F508del-CFTR homozygotes, the KRT8/KRT18 heterodimeric intermediary filaments of the cytoskeleton apparently are an essential component for the proper targeting of CFTR to the apical membrane in epithelial cells.
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Affiliation(s)
- Frauke Stanke
- Department of Pediatrics, Hannover Medical School, Hannover, Germany.
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Assessment of CFTR function in homozygous R117H-7T subjects. J Cyst Fibros 2011; 10:326-32. [PMID: 21507732 DOI: 10.1016/j.jcf.2011.03.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Revised: 03/04/2011] [Accepted: 03/22/2011] [Indexed: 11/20/2022]
Abstract
BACKGROUND R117H is a frequent missense mutation included in most CFTR mutation panels. However knowledge about the residual function of R117H-CFTR channels in cystic fibrosis-affected organs, e.g. airways, intestines and sweat glands is presently lacking. METHODS We evaluated clinical CF symptoms and assessed CFTR function by sweat tests, nasal potential difference and intestinal current measurements in 2 homozygous R117H individuals (7T variant). RESULTS The CFTR activity in airways and intestine was within the normal range. However both individuals presented with a borderline sweat test and the male patient was infertile. CONCLUSIONS The lack of impact of the R117H mutation on chloride secretion in intestine and nose contrasts with the ~80% loss of CFTR activity reported in patch clamp studies. Apparently CFTR activity is not rate-limiting for chloride secretion in both tissues at levels >20% of normal, or compensatory factors may operate that are absent in heterologous host cells in vitro.
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Abstract
In the past three decades, scientists have had immense success in identifying genes and their variants that contribute to an array of diseases. While the identification of such genetic variants has informed our knowledge of the etiologic bases of diseases, there continues to be a substantial gap in our understanding of the factors that modify disease severity. Monogenic diseases provide an opportunity to identify modifiers as they have uniform etiology, detailed phenotyping of affected individuals, and familial clustering. Cystic fibrosis (CF) is among the more common life-shortening recessive disorders that displays wide variability in clinical features and survival. Considerable progress has been made in elucidating the contribution of genetic and nongenetic factors to CF. Allelic variation in CFTR, the gene responsible for CF, correlates with some aspects of the disease. However, lung function, neonatal intestinal obstruction, diabetes, and anthropometry display strong genetic control independent of CFTR, and candidate gene studies have revealed genetic modifiers underlying these traits. The application of genome-wide techniques holds great promise for the identification of novel genetic variants responsible for the heritable features and complications of CF. Since the genetic modifiers are known to alter the course of disease, their protein products become immediate targets for therapeutic intervention.
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Affiliation(s)
- Garry R Cutting
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Cystic fibrosis transmembrane conductance regulator protein repair as a therapeutic strategy in cystic fibrosis. Curr Opin Pulm Med 2011; 16:591-7. [PMID: 20829696 DOI: 10.1097/mcp.0b013e32833f1d00] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
PURPOSE OF REVIEW Recent progress in understanding the production, processing, and function of the cystic fibrosis gene product, the cystic fibrosis transmembrane conductance regulator (CFTR), has revealed new therapeutic targets to repair the mutant protein. Classification of CFTR mutations and new treatment strategies to address each will be described here. RECENT FINDINGS High-throughput screening and other drug discovery efforts have identified small molecules that restore activity to mutant CFTR. Compounds such as VX-770 that potentiate CFTR have demonstrated exciting results in recent clinical trials and demonstrate robust effects across several CFTR mutation classes in the laboratory. A number of novel F508del CFTR processing correctors restore protein to the cell surface and improve ion channel function in vitro and are augmented by coadministration of CFTR potentiators. Ongoing discovery efforts that target protein folding, CFTR trafficking, and cell stress have also indicated promising results. Aminoglycosides and the novel small molecule ataluren induce translational readthrough of nonsense mutations in CFTR and other genetic diseases in vitro and in vivo and have shown activity in proof of concept trials, and ataluren is now being studied in confirmatory trials. SUMMARY An improved understanding of the molecular mechanisms underlying the basic genetic defect in cystic fibrosis have led to new treatment strategies to repair the mutant protein.
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Stanke F, Becker T, Kumar V, Hedtfeld S, Becker C, Cuppens H, Tamm S, Yarden J, Laabs U, Siebert B, Fernandez L, Macek M, Radojkovic D, Ballmann M, Greipel J, Cassiman JJ, Wienker TF, Tümmler B. Genes that determine immunology and inflammation modify the basic defect of impaired ion conductance in cystic fibrosis epithelia. J Med Genet 2010; 48:24-31. [PMID: 20837493 PMCID: PMC3003880 DOI: 10.1136/jmg.2010.080937] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Background The cystic fibrosis (CF) basic defect, caused by dysfunction of the apical chloride channel CFTR in the gastrointestinal and respiratory tract epithelia, has not been employed so far to support the role of CF modifier genes. Methods Patients were selected from 101 families with a total of 171 F508del-CFTR homozygous CF patients to identify CF modifying genes. A candidate gene based association study of 52 genes on 16 different chromosomes with a total of 182 genetic markers was performed. Differences in haplotype and/or diplotype distribution between case and reference CF subpopulations were analysed. Results Variants at immunologically relevant genes were associated with the manifestation of the CF basic defect (0.01<Praw<0.0001 at IL1B, TLR9, TNFα, CD95, STAT3 and TNFR). The intragenic background of F508del-CFTR chromosomes determined disease severity and manifestation of the basic defect (Praw=0.0009). Allele distributions comparing transmitted and non-transmitted alleles were distorted at several loci unlinked to CFTR. Conclusions The inherited capabilities of the innate and adaptive immune system determine the manifestation of the CF basic defect. Variants on F508del-CFTR chromosomes contribute to the observed patient-to-patient variability among F508del-CFTR homozygotes. A survivor effect, manifesting as a transmission disequilibrium at many loci, is consistent with the improvement of clinical care over the last decades, resulting in a depletion of risk alleles at modifier genes. Awareness of non-genetic factors such as improvement of patient care over time is crucial for the interpretation of CF modifier studies.
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Affiliation(s)
- Frauke Stanke
- Department of Pediatrics, Hannover Medical School, Germany.
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48
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van Barneveld A, Stanke F, Tamm S, Siebert B, Brandes G, Derichs N, Ballmann M, Junge S, Tümmler B. Functional analysis of F508del CFTR in native human colon. Biochim Biophys Acta Mol Basis Dis 2010; 1802:1062-9. [PMID: 20696241 DOI: 10.1016/j.bbadis.2010.08.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 07/28/2010] [Accepted: 08/02/2010] [Indexed: 11/16/2022]
Abstract
The major cystic fibrosis mutation F508del has been classified by experiments in animal and cell culture models as a temperature-sensitive mutant defective in protein folding, processing and trafficking, but literature data on F508del CFTR maturation and function in human tissue are inconsistent. In the present study the molecular pathology of F508del CFTR was characterized in freshly excised rectal mucosa by bioelectric measurement of the basic defect and CFTR protein analysis by metabolic labelling or immunoblot. The majority of investigated F508del homozygous subjects expressed low amounts of complex-glycosylated mature F508del CFTR and low residual F508del CFTR-mediated chloride secretory activity in the rectal mucosa. The finding that some F508del CFTR escapes the ER quality control in vivo substantiates the hope that the defective processing and trafficking of F508del CFTR can be corrected by pharmacological agents.
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Affiliation(s)
- Andrea van Barneveld
- Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Hannover, Germany.
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Quantitative expression analyses of candidates for alternative anion conductance in cystic fibrosis mouse models. J Cyst Fibros 2010; 9:351-64. [PMID: 20624691 DOI: 10.1016/j.jcf.2010.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 04/30/2010] [Accepted: 06/14/2010] [Indexed: 01/25/2023]
Abstract
BACKGROUND Diversity of cystic fibrosis (CF) phenotype in patients with the same CFTR-mutation raised the hypothesis that other factors modulate the phenotype including "alternative" calcium-activated anion currents (CaCC). This study compares the mRNA expression levels of candidate CaCC mediators in CF mouse models with wild type controls. METHODS mBEST1, mBEST2, mCLC-3B, mCLC-4, mTTYH3, mTMEM16A, mTMEM16F, mTMEM16K, mCLCA1 to -6 and SLC26A9 mRNA were quantified in CF-relevant tissues in cftr(tm1Cam) and cftr(TgH(neoim)Hgu) mice and controls using real-time RT-qPCR. RESULTS No consistent differences were observed except for mTTYH3 which was significantly down-regulated throughout the intestinal tract of cftr(tm1Cam) mice. CONCLUSIONS Down-regulation of mTTYH3 may point towards its involvement in the complex CF pathology. However, the markedly reduced expression argues against a direct compensatory action as an alternative anion conductance. If any of the other candidates plays a role as modulator, factors other than transcriptional regulation and mRNA stability may be involved.
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50
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Rowe SM, Pyle LC, Jurkevante A, Varga K, Collawn J, Sloane PA, Woodworth B, Mazur M, Fulton J, Fan L, Li Y, Fortenberry J, Sorscher EJ, Clancy JP. DeltaF508 CFTR processing correction and activity in polarized airway and non-airway cell monolayers. Pulm Pharmacol Ther 2010; 23:268-78. [PMID: 20226262 DOI: 10.1016/j.pupt.2010.02.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 02/13/2010] [Accepted: 02/17/2010] [Indexed: 12/21/2022]
Abstract
We examined the activity of DeltaF508 cystic fibrosis transmembrane conductance regulator (CFTR) stably expressed in polarized cystic fibrosis bronchial epithelial cells (CFBE41o(-)) human airway cells and Fisher Rat Thyroid (FRT) cells following treatment with low temperature and a panel of small molecule correctors of DeltaF508 CFTR misprocessing. Corr-4a increased DeltaF508 CFTR-dependent Cl(-) conductance in both cell types, whereas treatment with VRT-325 or VRT-640 increased activity only in FRT cells. Total currents stimulated by forskolin and genistein demonstrated similar dose/response effects to Corr-4a treatment in each cell type. When examining the relative contribution of forskolin and genistein to total stimulated current, CFBE41o(-) cells had smaller forskolin-stimulated I(sc) following either low temperature or corr-4a treatment (10-30% of the total I(sc) produced by the combination of both CFTR agonists). In contrast, forskolin consistently contributed greater than 40% of total I(sc) in DeltaF508 CFTR-expressing FRT cells corrected with low temperature, and corr-4a treatment preferentially enhanced forskolin dependent currents only in FRT cells (60% of total I(sc)). DeltaF508 CFTR cDNA transcript levels, DeltaF508 CFTR C band levels, or cAMP signaling did not account for the reduced forskolin response in CFBE41o(-) cells. Treatment with non-specific inhibitors of phosphodiesterases (papaverine) or phosphatases (endothall) did not restore DeltaF508 CFTR activation by forskolin in CFBE41o(-) cells, indicating that the Cl(-) transport defect in airway cells is distal to cAMP or its metabolism. The results identify important differences in DeltaF508 CFTR activation in polarizing epithelial models of CF, and have important implications regarding detection of rescued of DeltaF508 CFTR in vivo.
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Affiliation(s)
- S M Rowe
- Department of Medicine, University of Alabama at Birmingham, 1530 3rd Ave. South, Birmingham, AL 35294-0005, United States.
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