BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
R560S: A class II CFTR mutation that is not rescued by current modulators

Participants in the publication
Nikhil T. Awatade (Author)
Sofia Ramalho (Author)
Iris A.L. Silva (Author)
Verónica Felício (Author)
Hugo M. Botelho (Author)
BioISI - Biosystems & Integrative Sciences Institute
Dep. Química e Bioquímica
Eyleen de Poel (Author)
Annelotte Vonk (Author)
Jeffrey M. Beekman (Author)
Carlos M. Farinha (Author)
Dep. Química e Bioquímica
BioISI
Margarida D. Amaral (Author)
Dep. Química e Bioquímica
BioISI

Summary
New therapies modulating defective CFTR have started to hit the clinic and others are in trial or under development. The endeavour of drug discovery for CFTR protein rescue is however difficult one since over 2000 mutations have been reported. For most of these, especially the rare ones, the associated defects, the respective functional class and their responsiveness to available modulators are still unknown. Our aim here was to characterize the rare R560S mutation using patient-derived materials (rectal biopsies and intestinal organoids) from one CF individual homozygous for this mutation, in parallel with cellular models expressing R560S-CFTR and to assess the functional and biochemical responses to CFTR modulators.\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\n\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\nMETHODS:\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\nIntestinal organoids were prepared from rectal biopsies and analysed by RT-PCR (to assess CFTR mRNA), by Western blot (to assess CFTR protein) and by forskolin-induced swelling (FIS) assay. A novel cell line expressing R560S-CFTR was generated by stably transducing the CFBE parental cell line and used to assess R560S-CFTR processing and function. Both intestinal organoids and the cellular model were used to assess efficacy of CFTR modulators in rescuing this mutation.\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\n\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\nRESULTS:\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\nOur results show that: R560S does not affect CFTR mRNA splicing; R560S affects CFTR protein processing, totally abrogating the production of its mature form; R560S-CFTR evidences no function as a Cl- channel; and none of the modulators tested rescued R560S-CFTR processing or function.\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\n\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\nCONCLUSION:\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\nAltogether, these results indicate that R560S is a class II mutation. However, unlike F508del, it cannot be rescued by any of the CFTR modulators tested.


Where published
Journal of Cystic Fibrosis

Publication Identifiers
ISSN - 1569-1993

Publisher
Elsevier BV



Document Identifiers
URL - http://dx.doi.org/10.1016/j.jcf.2018.07.001
DOI - https://doi.org/10.1016/j.jcf.2018.07.001

Rankings
SCIMAGO Q1 (2020) - 2.049 - Pulmonary and Respiratory Medicine
SCIMAGO Q1 (2020) - 2.049 - Pediatrics, Perinatology and Child Health
Web Of Science Q1 (2020) - 5.482 - RESPIRATORY SYSTEM - SCIE
SCOPUS Q1 (2019) - 6.6 - Pediatrics, Perinatology and Child Health
Web Of Science Q1 (2020) - 5.482 - RESPIRATORY SYSTEM - SCIE
SCIMAGO Q1 (2020) - 2.049 - Pediatrics, Perinatology and Child Health
SCOPUS Q1 (2019) - 6.6 - Pulmonary and Respiratory Medicine

Keywords
Ex vivo biomarkers Intestinal organoids Rare mutations R560S CFTR CFTR modulators