scholarly journals Robust W1282X-CFTR rescue by a small molecule GSPT1 degrader

2021 ◽  
Author(s):  
Rhianna E Lee ◽  
Catherine A Lewis ◽  
Lihua He ◽  
Samuel C Gallant ◽  
Teresa M Mascenik ◽  
...  
Keyword(s):  
Cell Lines ◽  
Treatment Options ◽  
Airway Epithelial Cells ◽  
Primary Cell ◽  
Transmembrane Conductance Regulator ◽  
Airway Epithelial ◽  
Primary Cells ◽  
Premature Termination Codons ◽  
Trade Name ◽  
Cf Transmembrane Conductance Regulator

With the approval of elexacaftor/tezacaftor/ivacaftor (trade name Trikafta), the vast majority of people with cystic fibrosis (CF) are eligible for CF transmembrane conductance regulator (CFTR) modulator therapy. Remaining individuals have premature termination codons or rare CFTR variants with limited treatment options. Although clinical modulator response can be reliably predicted using primary airway epithelial cells, primary cells carrying rare CFTR variants are scarce. To overcome this obstacle, these cells can be expanded by overexpression of mouse Bmi-1 and human TERT (hTERT). We therefore used this approach to develop two non-CF and three CF (F508del/F508del, F508del/S492F, W1282X/W1282X) nasal cell lines and two W1282X/W1282X bronchial cell lines. Bmi-1/hTERT cell lines recapitulated primary cell morphology and ion transport function. The F508del/F508del and F508del/S492F cell lines robustly responded to Trikafta, which was mirrored in the parent primary cells and the cell donors' clinical response. CC-90009, a novel cereblon E3 ligase modulator targeting the GSPT1 protein, rescued ~20% of wildtype CFTR function in our panel of W1282X/W1282X cell lines and primary cells. Intriguingly, CC-90009 also diminished epithelial sodium channel function. These studies demonstrate that Bmi-1/hTERT cell lines faithfully mirror primary cell responses to CFTR modulators and illustrate novel therapeutic approaches for the W1282X CFTR variant.

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.

Treating the Airway Consequences of Cystic Fibrosis Transmembrane Conductance Regulator Dysfunction

2019 ◽  
Vol 40 (06) ◽  
pp. 751-761
Author(s):  
Demet Toprak ◽  
Chelsea Davis ◽  
Margaret Rosenfeld
Keyword(s):  
Cystic Fibrosis ◽  
Airway Epithelial Cells ◽  
Transmembrane Conductance Regulator ◽  
Airway Epithelial ◽  
National Guidelines ◽  
Transmembrane Conductance ◽  
Infection And Inflammation ◽  
Surface Liquid ◽  
Cf Transmembrane Conductance Regulator ◽  
Cystic Fibrosis Transmembrane

AbstractIn cystic fibrosis (CF), absent or dysfunctional CF transmembrane conductance regulator (CFTR) on the surface of airway epithelial cells causes abnormal mucociliary clearance, leading to chronic endobronchial infection and inflammation, in turn resulting in life-shortening progressive obstructive lung disease and structural airway damage. Fortunately, CF-specific therapies have been developed that improve lung function and reduce pulmonary exacerbations, contributing significantly to improved survival over the past 4 decades. Therapies not originally developed for CF, such as bronchodilators and corticosteroids, are also widely used by people living with CF. Therapies to be reviewed in this article include mucolytics, airway surface liquid hydrators, anti-inflammatory medications, bronchodilators, inhaled and oral antibiotics, and airway clearance techniques. Determining which therapies to utilize can be challenging, as there is variable evidence for each treatment, differing national guidelines, few head-to-head studies, potential for drug–drug interactions, and synergistic toxicities, as well as issues with burden of care. In this review, we summarize the mechanism of action and available evidence, and compare national guidelines for each major medication used to treat the airway consequences of CFTR dysfunction.

scholarly journals Chlorzoxazone or 1-EBIO increases Na+absorption across cystic fibrosis airway epithelial cells

2001 ◽  
Vol 281 (5) ◽  
pp. L1123-L1129 ◽  
Author(s):  
Lin Gao ◽  
James R. Yankaskas ◽  
Catherine M. Fuller ◽  
Eric J. Sorscher ◽  
Sadis Matalon ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Short Circuit ◽  
Fold Increase ◽  
Short Circuit Current ◽  
Airway Disease ◽  
Airway Epithelial Cells ◽  
Transmembrane Conductance Regulator ◽  
Airway Epithelial ◽  
Cystic Fibrosis Airway ◽  
Cf Transmembrane Conductance Regulator

Previous studies demonstrated that chlorzoxazone or 1-ethyl-2-benzimidazolinone (1-EBIO) enhances transepithelial Cl− secretion by increasing basolateral K+ conductance ( G K) (Singh AK, Devor DC, Gerlach AC, Gondor M, Pilewski JM, and Bridges RJ. J Pharmacol Exp Ther 292: 778–787, 2000). Hence these compounds may be useful to treat cystic fibrosis (CF) airway disease. The goal of the present study was to determine whether chlorzoxazone or 1-EBIO altered ion transport across ΔF508-CF transmembrane conductance regulator homozygous CFT1 airway cells. CFT1 monolayers exhibited a basal short-circuit current that was abolished by apical amiloride (inhibition constant 320 nM) as expected for Na+ absorption. The addition of chlorzoxazone (400 μM) or 1-EBIO (2 mM) increased the amiloride-sensitive I sc ∼2.5-fold. This overlapping specificity may preclude use of these compounds as CF therapeutics. Assaying for changes in the basolateral G K with a K+ gradient plus the pore-forming antibiotic amphotericin B revealed that chlorzoxazone or 1-EBIO evoked an ∼10-fold increase in clotrimazole-sensitive G K. In contrast, chlorzoxazone did not alter epithelial Na+ channel-mediated currents across basolateral-permeabilized monolayers or in Xenopus oocytes. These data further suggest that alterations in basolateral G K alone can modulate epithelial Na+ transport.

Role of CFTR in Airway Disease

1999 ◽  
Vol 79 (1) ◽  
pp. S215-S255 ◽  
Author(s):  
JOSEPH M. PILEWSKI ◽  
RAYMOND A. FRIZZELL
Keyword(s):  
Lung Disease ◽  
Mucociliary Clearance ◽  
Airway Disease ◽  
Airway Epithelial Cells ◽  
Transmembrane Conductance Regulator ◽  
Airway Epithelial ◽  
Gene Encoding ◽  
Water Secretion ◽  
Cf Transmembrane Conductance Regulator

Pilewski, Joseph M., and Raymond A. Frizzell. Role of CFTR in Airway Disease. Physiol. Rev. 79, Suppl.: S215–S255, 1999. — Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR), which accounts for the cAMP-regulated chloride conductance of airway epithelial cells. Lung disease is the chief cause of morbidity and mortality in CF patients. This review focuses on mechanisms whereby the deletion or impairment of CFTR chloride channel function produces lung disease. It examines the major themes of the channel hypothesis of CF, which involve impaired regulation of airway surface fluid volume or composition. Available evidence indicates that the effect of CFTR deletion alters physiological functions of both surface and submucosal gland epithelia. At the airway surface, deletion of CFTR causes hyperabsorption of sodium chloride and a reduction in the periciliary salt and water content, which impairs mucociliary clearance. In submucosal glands, loss of CFTR-mediated salt and water secretion compromises the clearance of mucins and a variety of defense substances onto the airway surface. Impaired mucociliary clearance, together with CFTR-related changes in the airway surface microenvironment, leads to a progressive cycle of infection, inflammation, and declining lung function. Here, we provide the details of this pathophysiological cascade in the hope that its understanding will promote the development of new therapies for CF.

scholarly journals Ozone effect on inflammatory and proteomic profile of human macrophages and airway epithelial cells

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
L Falcone ◽  
E Aruffo ◽  
P Di Carlo ◽  
P Del Boccio ◽  
M C Cufaro ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Air Pollution ◽  
Epithelial Cells ◽  
Cell Lines ◽  
Urban Areas ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Proteomics Analysis ◽  
Human Macrophages ◽  
Tnf Α

Abstract Background Reactive oxygen species (ROS) and oxidative stress in the respiratory system are involved in lung inflammation and tumorigenesis. Ozone (O3) is one of the main components of air pollution in urban areas able to act as strong pro-oxidant agent, however its effects on human health is still poorly investigated. In this study the effect of O3 has been evaluated in THP-1 monocytes differentiated into macrophages with PMA and in HBEpC (primary human bronchial epithelial) cells, two model systems for in vitro studies and translational research. Methods Cell viability, ROS and pro-inflammatory cytokines like interleukin-8(IL-8) and tumor necrosis factor(TNF-α) have been tested in the above-mentioned cell lines not exposed to any kind of pollution (basal condition-b.c.) or exposed to O3 at a concentration of 120 ppb. In HBEpC a labelfree shotgun proteomics analysis has been also performed in the same conditions. Results Ozone significantly increased the production of IL-8 and TNF-α in THP-1 whereas no changes were shown in HBEpC. In both cell lines lipopolysaccharide(LPS) caused an increase of IL-8 and TNF-α production in b.c. and O3 treatment potentiated this effect. Ozone exposure increased ROS formation in a time dependent manner in both cell lines and in THP-1 cells a decrease in catalase activity was also shown. Finally, according to these data, functional proteomics analysis revealed that in HBEpC exposure to O3 many differential proteins are related to oxidative stress and inflammation. Conclusions Our results indicate that O3, at levels that can be reached in urban areas, causes an increase of pro-inflammatory agents either per se or potentiating the effect of immune response stimulators in cell models of human macrophages and human airway epithelial cells. Interestingly, the proteomic analysis showed that besides the dysregulated proteins, O3 induced the expression of AKR1D1 and AKR1B10, proteins recognized to play a significant role in cancer development. Key messages This study adds new pieces of information on the association between O3 exposure and detrimental effects on respiratory system. This study suggests the need for further research on the mechanisms involved and for a continued monitoring/re-evaluation of air pollution standards aimed at safeguarding human health.

Basal chloride currents in murine airway epithelial cells: modulation by CFTR

1998 ◽  
Vol 274 (4) ◽  
pp. C904-C913 ◽  
Author(s):  
R. Tarran ◽  
M. A. Gray ◽  
M. J. Evans ◽  
W. H. Colledge ◽  
R. Ratcliff ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Airway Epithelial Cells ◽  
Transmembrane Conductance Regulator ◽  
Airway Epithelial ◽  
Wild Type ◽  
Patch Clamp Technique ◽  
Chloride Currents ◽  
Cation Permeability ◽  
Current Voltage ◽  
Respiratory Cells

We have isolated ciliated respiratory cells from the nasal epithelium of wild-type and cystic fibrosis (CF) null mice and used the patch-clamp technique to investigate their basal conductances. Current-clamp experiments on unstimulated cells indicated the presence of K+ and Cl− conductances and, under certain conditions, a small Na+conductance. Voltage-clamp experiments revealed three distinct Cl− conductances. I tv-indep was time and voltage independent with a linear current-voltage ( I- V) plot; I v-actexhibited activation at potentials greater than ±50 mV, giving an S-shaped I- Vplot; and I hyp-act was activated by hyperpolarizing potentials and had an inwardly rectified I- Vplot. The current density sequence was I hyp-act = I v-act ≫ I tv-indep. These conductances had Cl−-to- N-methyl-d-glucamine cation permeability ratios of between 2.8 and 10.3 and were unaffected by tamoxifen, flufenamate, glibenclamide, DIDS, and 5-nitro-2-(3-phenylpropylamino) benzoic acid but were inhibited by Zn2+ and Gd3+. I tv-indep and I v-act were present in wild-type and CF cells at equal density and frequency. However, I hyp-actwas detected in only 3% of CF cells compared with 26% of wild-type cells, suggesting that this conductance may be modulated by cystic fibrosis transmembrane conductance regulator (CFTR).

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