Evaluation of CFTR Channel Functions and Responses to Modulators in Patients with Cystic Fibrosis who Have a Pathogenic F508del Variant in Their Genomes

2020 ◽  
Vol 36 (4) ◽  
pp. 69-73
Author(s):  
A.S. Efremova ◽  
Т.В. Bukharova ◽  
N.V. Petrova ◽  
N.Yu. Kashirskaya ◽  
Yu.L. Melyanovskaya ◽  
...  
Keyword(s):  
Higher Education ◽  
Cystic Fibrosis ◽  
Functional Activity ◽  
Channel Function ◽  
Intestinal Organoids ◽  
Highly Sensitive ◽  
Variant Genotype ◽  
Healthy Control ◽  
Rectal Biopsies ◽  
Cftr Modulators

Intestinal organoids derived from rectal biopsies of cystic fibrosis patients are a highly sensitive personalized method for evaluating the functional activity of the CFTR channel and the efficacy of target drugs. We examined four patients whose genotype contains the pathogenic F508del variant (three patients and one healthy heterozygous person). It was shown that F508del/F508del genotype (two patients) could be effectively corrected by CFTR modulators (VX-770 and VX-809). The modulators had no significant effect on the restoration of the chlorine CFTR channel function in a patient with the W361X/F508del genotype. The CFTR functional activity in the heterozygous F508del carrier was as high as in the healthy control. cystic fibrosis, intestinal organoids, genetic F508del variant, genotype, forskolin-induced swelling (FIS) assay, CFTR modulators This study was supported by the Ministry of Science and Higher Education as part of a State Assignment for RCMG.

scholarly journals Correction of CFTR function in intestinal organoids to guide treatment of cystic fibrosis

2020 ◽  
Vol 57 (1) ◽  
pp. 1902426 ◽  
Author(s):  
Anabela S. Ramalho ◽  
Eva Fürstová ◽  
Annelotte M. Vonk ◽  
Marc Ferrante ◽  
Catherine Verfaillie ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Clinical Data ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Vast Number ◽  
Sweat Chloride ◽  
Intestinal Organoids ◽  
Rectal Biopsies ◽  
Cftr Modulators

RationaleGiven the vast number of cystic fibrosis transmembrane conductance regulator (CFTR) mutations, biomarkers predicting benefit from CFTR modulator therapies are needed for subjects with cystic fibrosis (CF).ObjectivesTo study CFTR function in organoids of subjects with common and rare CFTR mutations and evaluate correlations between CFTR function and clinical data.MethodsIntestinal organoids were grown from rectal biopsies in a cohort of 97 subjects with CF. Residual CFTR function was measured by quantifying organoid swelling induced by forskolin and response to modulators by quantifying organoid swelling induced by CFTR correctors, potentiator and their combination. Organoid data were correlated with clinical data from the literature.ResultsAcross 28 genotypes, residual CFTR function correlated (r2=0.87) with sweat chloride values. When studying the same genotypes, CFTR function rescue by CFTR modulators in organoids correlated tightly with mean improvement in lung function (r2=0.90) and sweat chloride (r2=0.95) reported in clinical trials. We identified candidate genotypes for modulator therapy, such as E92K, Q237E, R334W and L159S. Based on organoid results, two subjects started modulator treatment: one homozygous for complex allele Q359K_T360K, and the second with mutation E60K. Both subjects had major clinical benefit.ConclusionsMeasurements of residual CFTR function and rescue of function by CFTR modulators in intestinal organoids correlate closely with clinical data. Our results for reference genotypes concur with previous results. CFTR function measured in organoids can be used to guide precision medicine in patients with CF, positioning organoids as a potential in vitro model to bring treatment to patients carrying rare CFTR mutations.

Functional tests for assessment of residual CFTR channel activity and personalized selection of efficacious CFTR-modulators for cystic fibrosis patients with ‘mild’ and ‘severe’ genetic variants

2021 ◽  
Vol 31 (2) ◽  
pp. 167-177
Author(s):  
E. L. Amelina ◽  
A. S. Efremova ◽  
Yu. L. Melyanovskaya ◽  
N. V. Bulatenko ◽  
T. B. Bukharova ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Clinical Data ◽  
Genetic Variant ◽  
Functional Tests ◽  
Channel Activity ◽  
Intestinal Organoids ◽  
Cftr Mutations ◽  
Rectal Biopsies ◽  
Cftr Modulators

Intestinal current measurement (ICM) and forskolin-induced swelling (FIS) assay in human intestinal organoids from rectal biopsies of cystic fibrosis (CF) patients are the new functional tests for assessment of CFTR channel activity that are widely used in the leading laboratories worldwide for scientific and clinical studies.The aim of the study was to assess the use of the new functional tests in adult CF patients with identified N1303K and R334W CFTR gene variants.Methods. Rectal suction biopsies were obtained from the two CF patients aged 36 and 27 years with N1303K/3821delT and R334W/F508del CFTR mutations, respectively. Results of the ICM and FIS assay in intestinal organoids were compared to the clinical data.Results. ICM has demonstrated that R334W is a ‘mild’ genetic variant with high residual CFTR channel activity. At the same time, N1303K is a ‘severe’ genetic variant and leads to a severe loss of CFTR channel function. These findings correlate with the clinical data. CFTR modulators compensate for the reduced activity of the R334W CFTR variant, as shown by the FIS assay. But there was a limited response of the forskolin-stimulated organoids to VX-770 potentiator and VX-809 corrector in the cells with N1303K genetic variant.Conclusion. ICM and FIS assay in human intestinal organoids are reliable methods for quantification of CFTR channel activity. They can also predict the efficacy of the targeted therapy in CF patients in vivo.

scholarly journals Personalized Medicine Based on Nasal Epithelial Cells: Comparative Studies with Rectal Biopsies and Intestinal Organoids

2021 ◽  
Vol 11 (5) ◽  
pp. 421
Author(s):  
Iris A. L. Silva ◽  
Violeta Railean ◽  
Aires Duarte ◽  
Margarida D. Amaral
Keyword(s):  
Clinical Trials ◽  
Personalized Medicine ◽  
Unmet Need ◽  
Rare Mutations ◽  
Intestinal Organoids ◽  
Bona Fide ◽  
The Individual ◽  
Rectal Biopsies ◽  
Effective Drugs ◽  
Cftr Modulators

As highly effective CFTR modulator therapies (HEMT) emerge, there is an unmet need to find effective drugs for people with CF (PwCF) with ultra-rare mutations who are too few for classical clinical trials and for whom there are no drug discovery programs. Therefore, biomarkers reliably predicting the benefit from CFTR modulator therapies are essential to find effective drugs for PwCF through personalized approaches termed theranostics. Here, we assess CFTR basal function and the individual responses to CFTR modulators in primary human nasal epithelial (pHNE) cells from PwCF carrying rare mutations and compare these measurements with those in native rectal biopsies and intestinal organoids, respectively, in the same individual. The basal function in pHNEs shows good correlation with CFTR basal function in rectal biopsies. In parallel, CFTR rescue in pHNEs by CFTR modulators correlates to that in intestinal organoids. Altogether, results show that pHNEs are a bona fide theranostic model to assess CFTR rescue by CFTR modulator drugs, in particular for PwCF and rare mutations.

Discovery of CFTR modulators for the treatment of cystic fibrosis

2021 ◽  
pp. 1-17
Author(s):  
Miquéias Lopes-Pacheco ◽  
Nicoletta Pedemonte ◽  
Guido Veit
Keyword(s):  
Cystic Fibrosis ◽  
Cftr Modulators

scholarly journals Impact of Airway Inflammation on the Efficacy of CFTR Modulators

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3260
Author(s):  
Carla M. P. Ribeiro ◽  
Martina Gentzsch
Keyword(s):  
Cystic Fibrosis ◽  
Airway Inflammation ◽  
Primary Cultures ◽  
Lavage Fluid ◽  
Improved Outcomes ◽  
Inflammatory Stimuli ◽  
Infection And Inflammation ◽  
The Impact ◽  
Cftr Modulators

Defective CFTR biogenesis and activity in cystic fibrosis airways leads to airway dehydration and impaired mucociliary clearance, resulting in chronic airway infection and inflammation. Most cystic fibrosis patients have at least one copy of the F508del CFTR mutation, which results in a protein retained in the endoplasmic reticulum and degraded by the proteosomal pathway. CFTR modulators, e.g., correctors, promote the transfer of F508del to the apical membrane, while potentiators increase CFTR activity. Corrector and potentiator double therapies modestly improve lung function, whereas triple therapies with two correctors and one potentiator indicate improved outcomes. Enhanced F508del rescue by CFTR modulators is achieved by exposing F508del/F508del primary cultures of human bronchial epithelia to relevant inflammatory stimuli, i.e., supernatant from mucopurulent material or bronchoalveolar lavage fluid from human cystic fibrosis airways. Inflammation enhances the biochemical and functional rescue of F508del by double or triple CFTR modulator therapy and overcomes abrogation of CFTR correction by chronic VX-770 treatment in vitro. Furthermore, the impact of inflammation on clinical outcomes linked to CFTR rescue has been recently suggested. This review discusses these data and possible mechanisms for airway inflammation-enhanced F508del rescue. Expanding the understanding of how airway inflammation improves CFTR rescue may benefit CF patients.

scholarly journals Progress in precision medicine in cystic fibrosis: a focus on CFTR modulator therapy

Breathe ◽  
2021 ◽  
Vol 17 (4) ◽  
pp. 210112
Author(s):  
Daniel H. Tewkesbury ◽  
Rebecca C. Robey ◽  
Peter J. Barry
Keyword(s):  
Cystic Fibrosis ◽  
Precision Medicine ◽  
Real World ◽  
Chloride Ion ◽  
Transmembrane Conductance Regulator ◽  
Therapeutic Approaches ◽  
Transmembrane Conductance ◽  
Cftr Protein ◽  
Cystic Fibrosis Transmembrane ◽  
Cftr Modulators

The genetic multisystem condition cystic fibrosis (CF) has seen a paradigm shift in therapeutic approaches within the past decade. Since the first clinical descriptions in the 1930s, treatment advances had focused on the downstream consequences of a dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) chloride ion channel. The discovery of the gene that codes for CFTR and an understanding of the way in which different genetic mutations lead to disruption of normal CFTR function have led to the creation and subsequent licensing of drugs that target this process. This marks an important move towards precision medicine in CF and results from clinical trials and real-world clinical practice have been impressive. In this review we outline how CFTR modulator drugs restore function to the CFTR protein and the progress that is being made in this field. We also describe the real-world impact of CFTR modulators on both pulmonary and multisystem complications of CF and what this will mean for the future of CF care.

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