{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,31]],"date-time":"2026-10-31T05:26:50Z","timestamp":1793424410956,"version":"4.5.0"},"reference-count":39,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2022,4,14]],"date-time":"2022-04-14T00:00:00Z","timestamp":1649894400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Bambino Ges\u00f9 Children's Hospital","award":["Ricerca Corrente 2021"],"award-info":[{"award-number":["Ricerca Corrente 2021"]}]},{"name":"Fondazione Italiana Fibrosis Cistica","award":["FFC #3\/2015"],"award-info":[{"award-number":["FFC #3\/2015"]}]},{"name":"Fondazione Italiana Fibrosis Cistica","award":["FFC #9\/2020"],"award-info":[{"award-number":["FFC #9\/2020"]}]},{"name":"CFF-USA","award":["DEJONG16GO"],"award-info":[{"award-number":["DEJONG16GO"]}]},{"name":"Dutch CF Foundation, NCFS","award":["HIT-CF2"],"award-info":[{"award-number":["HIT-CF2"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JPM"],"abstract":"<jats:p>Background: The effect of presently available CFTR modulator combinations, such as elexacaftor (ELX), tezacaftor (TEZ), and ivacaftor (IVA), on rare CFTR alleles is often unknown. Several assays have been developed, such as forskolin-induced swelling (FIS), to evaluate the rescue of such uncommon CFTR alleles both by established and novel modulators in patient-derived primary cell cultures (organoids). Presently, we assessed the CFTR-mediated electrical current across rectal organoid-derived epithelial monolayers. This technique, which allows separate measurement of CFTR-dependent chloride or bicarbonate transport, was used to assess the effect of ELX\/TEZ\/IVA on two rare CFTR variants. Methods: Intestinal organoid cultures were established from rectal biopsies of CF patients carrying the rare missense mutations E193K or R334W paired with F508del. The effect of the CFTR modulator combination ELX\/TEZ\/IVA on CFTR-mediated Cl\u2212 and HCO3\u2212 secretion was assessed in organoid-derived intestinal epithelial monolayers. Non-CF organoids were used for comparison. Clinical biomarkers (sweat chloride, FEV1) were monitored in patients receiving modulator therapy. Results: ELX\/TEZ\/IVA markedly enhanced CFTR-mediated bicarbonate and chloride transport across intestinal epithelium of both patients. Consistent with the rescue of CFTR function in cultured intestinal cells, ELX\/TEZ\/IVA therapy improved biomarkers of CFTR function in the R334W\/F508del patient. Conclusions: Current measurements in organoid-derived intestinal monolayers can readily be used to monitor CFTR-dependent epithelial Cl\u2212 and HCO3\u2212 transport. This technique can be explored to assess the functional consequences of rare CFTR mutations and the efficacy of CFTR modulators. We propose that this functional CFTR assay may guide personalized medicine in patients with CF-like clinical manifestations as well as in those carrying rare CFTR mutations.<\/jats:p>","DOI":"10.3390\/jpm12040632","type":"journal-article","created":{"date-parts":[[2022,4,18]],"date-time":"2022-04-18T04:21:28Z","timestamp":1650255688000},"page":"632","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["Theratyping of the Rare CFTR Variants E193K and R334W in Rectal Organoid-Derived Epithelial Monolayers"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1493-9767","authenticated-orcid":false,"given":"Fabiana","family":"Ciciriello","sequence":"first","affiliation":[{"name":"Cystic Fibrosis Unit, Department of Pediatric Subspecialties, Bambino Ges\u00f9 Children\u2019s Hospital, IRCCS, 00165 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0814-188X","authenticated-orcid":false,"given":"Marcel J. C.","family":"Bijvelds","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology & Hepatology, Erasmus MC University Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4333-791X","authenticated-orcid":false,"given":"Federico","family":"Alghisi","sequence":"additional","affiliation":[{"name":"Cystic Fibrosis Unit, Department of Pediatric Subspecialties, Bambino Ges\u00f9 Children\u2019s Hospital, IRCCS, 00165 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kelly F.","family":"Meijsen","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology & Hepatology, Erasmus MC University Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luca","family":"Cristiani","sequence":"additional","affiliation":[{"name":"Cystic Fibrosis Unit, Department of Pediatric Subspecialties, Bambino Ges\u00f9 Children\u2019s Hospital, IRCCS, 00165 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2739-4014","authenticated-orcid":false,"given":"Claudio","family":"Sorio","sequence":"additional","affiliation":[{"name":"Department of Medicine, General Pathology Division, University of Verona, 37134 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5276-1595","authenticated-orcid":false,"given":"Paola","family":"Melotti","sequence":"additional","affiliation":[{"name":"Cystic Fibrosis Centre, Azienda Ospedaliera Universitaria Integrata of Verona, 37126 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2549-0523","authenticated-orcid":false,"given":"Alessandro G.","family":"Fiocchi","sequence":"additional","affiliation":[{"name":"Cystic Fibrosis Unit, Department of Pediatric Subspecialties, Bambino Ges\u00f9 Children\u2019s Hospital, IRCCS, 00165 Rome, Italy"},{"name":"Division of Allergy, Bambino Ges\u00f9 Children\u2019s Hospital, IRCCS, 00165 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vincenzina","family":"Lucidi","sequence":"additional","affiliation":[{"name":"Cystic Fibrosis Unit, Department of Pediatric Subspecialties, Bambino Ges\u00f9 Children\u2019s Hospital, IRCCS, 00165 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hugo R.","family":"De Jonge","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology & Hepatology, Erasmus MC University Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,4,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1016\/S0140-6736(03)12567-6","article-title":"Cystic fibrosis","volume":"361","author":"Ratjen","year":"2003","journal-title":"Lancet"},{"key":"ref_2","unstructured":"Zolin, A., Orenti, A., Nahrlich, L., Jung, A., and van Rens, J. (2020, January 01). ECFS Patient Registry Annual Report 2018. Available online: https:\/\/www.ecfs.eu\/projects\/ecfs-patientregistry\/annual-reports."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1080\/17460441.2021.1912732","article-title":"Discovery of CFTR modulators for the treatment of cystic fibrosis","volume":"16","author":"Pedemonte","year":"2021","journal-title":"Expert Opin. 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