CFTR variants are associated with chronic bronchitis in smokers

2022 ◽  
pp. 2101994
Author(s):  
Aabida Saferali ◽  
Dandi Qiao ◽  
Wonji Kim ◽  
Karen Raraigh ◽  
Hara Levy ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Chronic Bronchitis ◽  
Meta Analysis ◽  
P Value ◽  
Transmembrane Conductance Regulator ◽  
Loss Of Function ◽  
Transmembrane Conductance ◽  
Clinical Consequences ◽  
History Of ◽  
Coding Variants

IntroductionLoss of function variants in both copies of the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF); however, there is evidence that reduction in CFTR function due to the presence of one deleterious variant can have clinical consequences. Here, we hypothesize that CFTR variants in individuals with a history of smoking are associated with COPD and related phenotypes.MethodsWhole genome sequencing was performed through the NHLBI TOPMed program in 8597 subjects from the COPDGene study, an observational study of current and former smokers. We extracted clinically annotated CFTR variants and performed single variant and variant-set testing for COPD and related phenotypes. Replication was performed in 2,118 subjects from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study.ResultsWe identified 301 coding variants within the CFTR gene boundary: 147 of these have been reported in individuals with CF, including 36 CF-causing variants. We found that CF causing variants were associated with chronic bronchitis in variant-set testing in COPDGene (one sided p-value=0.0025, OR=1.53) and in meta-analysis of COPDGene and ECLIPSE (one sided p-value=0.0060, OR=1.52). Single variant testing revealed that the F508del variant was associated with chronic bronchitis in COPDGene (one sided p-value=0.015, OR=1.47). In addition, we identified 32 subjects with two or more CFTR variants on separate alleles, and these subjects were enriched for COPD cases (p=0.010).ConclusionsCigarette smokers who carry one deleterious CFTR variant have higher rates of chronic bronchitis, while presence of two CFTR variants may be associated with COPD. These results indicate that genetically-mediated reduction in CFTR function contributes to COPD related phenotypes, in particular chronic bronchitis.

scholarly journals Quantitative Evaluation of CFTR Pre-mRNA Splicing Dependent on the (TG)mTn Poly-Variant Tract

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 168
Author(s):  
Manuela Sterrantino ◽  
Andrea Fuso ◽  
Silvia Pierandrei ◽  
Sabina Maria Bruno ◽  
Giancarlo Testino ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Transmembrane Conductance Regulator ◽  
Functional Effect ◽  
Transmembrane Conductance ◽  
Therapeutic Consequences ◽  
Clinical Consequences ◽  
Exon 9 ◽  
The Many ◽  
Cystic Fibrosis Transmembrane ◽  
Exon 10

Genetic analysis in cystic fibrosis (CF) is a difficult task. Within the many causes of variability and uncertainty, a major determinant is poor knowledge of the functional effect of most DNA variants of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. In turn, knowledge of the effect of a CFTR variant has dramatic diagnostic, prognostic and, in the era of CF precision medicine, also therapeutic consequences. One of the most challenging CFTR variants is the (TG)mTn haplotype, which has variable functional effect and controversial clinical consequences. The exact quantification of the anomalous splicing of CFTR exon 10 (in the HGVS name; exon 9 in the legacy name) and, consequently, of the residual wild-type functional CFTR mRNA, should be mandatory in clinical assessment of patients with potentially pathological haplotype of this tract. Here, we present a real time-based assay for the quantification of the proportion of exon 10+/exon 10− CFTR mRNA, starting from nasal brushing. Our assay proved rapid, economic and easy to perform. Specific primers used for this assay are either disclosed or commercially available, allowing any laboratory to easily perform it. A simplified analysis of the data is provided, facilitating the interpretation of the results. This method helps to enhance the comprehension of the genotype–phenotype relationship in CF and CFTR-related disorders (CFTR-RD), crucial for the diagnosis, prognosis and personalized therapy of CF.

Characterizing diverse orthologues of the cystic fibrosis transmembrane conductance regulator protein for structural studies

2015 ◽  
Vol 43 (5) ◽  
pp. 894-900 ◽  
Author(s):  
Naomi L. Pollock ◽  
Tracy L. Rimington ◽  
Robert C. Ford
Keyword(s):  
Cystic Fibrosis ◽  
Structural Data ◽  
Transmembrane Conductance Regulator ◽  
Loss Of Function ◽  
Transmembrane Conductance ◽  
Functional Studies ◽  
Regulator Protein ◽  
Organ Systems ◽  
Cftr Protein ◽  
Cystic Fibrosis Transmembrane

As an ion channel, the cystic fibrosis transmembrane conductance regulator (CFTR) protein occupies a unique niche within the ABC family. Orthologues of CFTR are extant throughout the animal kingdom from sharks to platypods to sheep, where the osmoregulatory function of the protein has been applied to differing lifestyles and diverse organ systems. In humans, loss-of-function mutations to CFTR cause the disease cystic fibrosis, which is a significant health burden in populations of white European descent. Orthologue screening has proved fruitful in the pursuit of high-resolution structural data for several membrane proteins, and we have applied some of the princples developed in previous studies to the expression and purification of CFTR. We have overexpressed this protein, along with evolutionarily diverse orthologues, in Saccharomyces cerevisiae and developed a purification to isolate it in quantities sufficient for structural and functional studies.

scholarly journals Differential Effects of Oleuropein and Hydroxytyrosol on Aggregation and Stability of CFTR NBD1-ΔF508 Domain

2021 ◽  
Vol 1 (3) ◽  
pp. 204-215
Author(s):  
Christopher S. Robinson ◽  
Jennifer A. Wyderko ◽  
Yeng Vang ◽  
Galen Martin ◽  
Robert T. Youker
Keyword(s):  
Cystic Fibrosis ◽  
Phenolic Compounds ◽  
Aggregate Size ◽  
Docking Studies ◽  
Antagonistic Effect ◽  
Transmembrane Conductance Regulator ◽  
Loss Of Function ◽  
Transmembrane Conductance ◽  
Differential Scanning Fluorimetry ◽  
And Function

Cystic Fibrosis (CF) is caused by loss of function mutations in the Cystic Fibrosis transmembrane conductance regulator (CFTR). The folding and assembly of CFTR is inefficient. Deletion of F508 in the first nucleotide binding domain (NBD1-ΔF508) further disrupts protein stability leading to endoplasmic reticulum retention and proteasomal degradation. Stabilization and prevention of NBD1-ΔF508 aggregation is critical to rescuing the folding and function of the entire CFTR channel. We report that the phenolic compounds Oleuropein and Hydroxytryosol reduce aggregation of NBD1-ΔF508. The NBD1-ΔF508 aggregate size was smaller in the presence of Hydroxytryosol as determined by dynamic light scattering. Neither phenolic compound increased the thermal stability of NBD1-ΔF508 as measured by differential scanning fluorimetry. Interestingly, Hydroxytyrosol inhibited the stabilizing effect of the indole compound BIA, a known stabilizer, on NBD1-ΔF508. Molecular docking studies predicted that Oleuropein preferred to bind in the F1-type core ATP-binding subdomain in NBD1. In contrast, Hydroxytyrosol preferred to bind in the α4/α5/α6 helical bundle of the ABCα subdomain of NBD1 next to the putative binding site for BIA. This result suggests that Hydroxytyrosol interferes with BIA binding, thus providing an explanation for the antagonistic effect on NBD1 stability upon incubation with both compounds. To our knowledge, these studies are the first to explore the effects of these two phenolic compounds on the aggregation and stability of NBD1-ΔF508 domain of CFTR.

scholarly journals Modulation of Ion Transport to Restore Airway Hydration in Cystic Fibrosis

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 453
Author(s):  
James A. Reihill ◽  
Lisa E. J. Douglas ◽  
S. Lorraine Martin
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cells ◽  
Genetic Disorder ◽  
Airway Epithelial Cells ◽  
Transmembrane Conductance Regulator ◽  
Airway Epithelial ◽  
Loss Of Function ◽  
Transmembrane Conductance ◽  
Infection And Inflammation ◽  
Cf Transmembrane Conductance Regulator

Cystic fibrosis (CF) is a life-limiting genetic disorder caused by loss-of-function mutations in the gene which codes for the CF transmembrane conductance regulator (CFTR) Cl− channel. Loss of Cl− secretion across the apical membrane of airway lining epithelial cells results in dehydration of the airway surface liquid (ASL) layer which impairs mucociliary clearance (MCC), and as a consequence promotes bacterial infection and inflammation of the airways. Interventions that restore airway hydration are known to improve MCC. Here we review the ion channels present at the luminal surface of airway epithelial cells that may be targeted to improve airway hydration and MCC in CF airways.

scholarly journals CFTR mRNAs with nonsense codons are degraded by the SMG6-mediated endonucleolytic pathway

2021 ◽  
Author(s):  
Edward Sanderlin ◽  
Melissa Keenan ◽  
Martin Mense ◽  
Alexey Revenko ◽  
Brett Monia ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Exon Junction Complex ◽  
Transmembrane Conductance Regulator ◽  
Loss Of Function ◽  
Transmembrane Conductance ◽  
Nonsense Mutations ◽  
Nonsense Mediated Decay ◽  
Nonsense Codon ◽  
Translational Readthrough ◽  
Nonsense Codons

Abstract Cystic fibrosis is caused by loss of function mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene resulting in severe lung disease. Nearly 10% of cystic fibrosis patients have at least one CFTR allele with a nonsense mutation that generates a nonsense codon in the mRNA. Nonsense mutations can result in significant reduction of gene expression partially due to rapid mRNA degradation through the nonsense-mediated decay (NMD) pathway. It has not been thoroughly investigated which branch of the NMD pathway governs the decay of CFTR mRNAs containing nonsense codons. Here we utilized antisense oligonucleotides targeting NMD factors to evaluate the regulation of nonsense codon-containing CFTR mRNAs by the NMD pathway. Interestingly, we found that CFTR mRNAs with G542X, R1162X, and W1282X nonsense codons require UPF2, UPF3, and exon junction complex proteins for NMD, whereas CFTR mRNAs with the Y122X nonsense codon do not. Furthermore, we demonstrated that all evaluated CFTR mRNAs harboring nonsense codons were degraded by the SMG6-mediated endonucleolytic pathway rather than the SMG5/SMG7-mediated exonucleolytic pathway. Finally, we found that stabilization of CFTR mRNAs by NMD inhibition alone improved functional W1282X protein production, and improved the efficiency of aminoglycoside translational readthrough of CFTR-Y122X, -G542X, and -R1162X mRNAs.

Diagnosis of cystic fibrosis in adulthood and eligibility for novel CFTR modulator therapy

2021 ◽  
pp. postgradmedj-2020-139278
Author(s):  
Hannah Farley ◽  
Sarah Poole ◽  
Stephen Chapman ◽  
William Flight
Keyword(s):  
Cystic Fibrosis ◽  
Chronic Respiratory Disease ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Radiological Data ◽  
Patient Database ◽  
Cftr Mutations ◽  
History Of ◽  
Autosomal Recessive Condition ◽  
Cystic Fibrosis Transmembrane

BackgroundCystic fibrosis (CF) is an autosomal recessive condition that primarily manifests as a chronic respiratory disease. CF is usually diagnosed in early childhood or through newborn screening although in a small but important group, diagnosis is not made until adulthood. Highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies are now available for most genetic causes of CF highlighting the importance of identifying people with late presentations of CF.AimWe aimed to identify the clinical characteristics of people diagnosed with CF in adulthood and their resulting eligibility for novel CFTR modulator therapies.DesignRetrospective single-centre cohort study.MethodsPatients diagnosed with CF at age 18 years or older were identified from a patient database. Paper and electronic medical records were reviewed and clinical, microbiological and radiological data at diagnosis were recorded.ResultsNineteen patients were identified. Median age at diagnosis was 38 years (range: 19–71) and 9 (47%) were female. All patients had a history of chronic respiratory symptoms and 18/19 (94%) had radiological evidence of bronchiectasis. All patients had two pathogenic CFTR mutations identified with 16/19 (84%) compound heterozygotes for the F508del mutation. The majority of patients had a CFTR genotype considered eligible for CFTR modulator therapy (84% and 89% according to European and US licences, respectively).ConclusionsAdult patients with unexplained chronic bronchiectasis should be thoroughly investigated for CF. A low index of suspicion will help to identify adults with undiagnosed CF who are likely to benefit from CFTR modulator therapy.

scholarly journals Enamel Pathology Resulting from Loss of Function in the Cystic Fibrosis Transmembrane Conductance Regulator in a Porcine Animal Model

2011 ◽  
Vol 194 (2-4) ◽  
pp. 249-254 ◽  
Author(s):  
Eugene H. Chang ◽  
Rodrigo S. Lacruz ◽  
Timothy G. Bromage ◽  
Pablo Bringas, Jr. ◽  
Michael J. Welsh ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Animal Model ◽  
Transmembrane Conductance Regulator ◽  
Loss Of Function ◽  
Transmembrane Conductance ◽  
Cystic Fibrosis Transmembrane
Sign in / Sign up

Export Citation Format

Share Document