Abstract
Cystic fibrosis, an autosomal recessive disease frequently diagnosed in the Caucasian population, is characterized by deficient Cl- transport due to mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. A second major hall-mark of the disease is Na+ hyperabsorption by the airways, mediated by the epithelial Na+ channel (ENaC). In this study, we report that in human airway epithelial CF15 cells treated with the CFTR corrector miglustat (n-butyldeoxynojyrimicin), whole-cell patch-clamp experiments showed reduced amiloride-sensitive ENaC current in parallel with a rescue of defective CFTR Cl- channel activity activated by forskolin and genistein. Similar results were obtained with cells maintained in culture at 27°C for 24 h before electrophysiology experiments. With monolayers of polarized CF15 cells, short-circuit current (Isc) measurements also show normalization of Na+ and Cl- currents. In excised nasal epithelium of cftrF508del/F508del mice, like with CF15 cells, we found normalization of amiloride-sensitive Isc. Moreover, oral administration of miglustat (6 days) decreased the amiloride-sensitive Isc in cftrF508del/F508del mice but had no effect on cftr-/- mice. Our results thus show that rescuing the trafficking-deficient F508del-CFTR by miglustat down-regulates Na+ absorption. A miglustat-based treatment of CF patients may thus have a beneficial effect both on Cl- and Na+ transports.
Footnotes
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This study was supported by specific grants from Vaincre La Mucoviscidose and MucoVie66. S.N. was supported by a studentship from MucoVie66.
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Part of this work were previously presented as an abstract as follows: Noel S, Wilke M, De Lange HR, and Becq F (2006) Rescue of F508del-CFTR processing defect by miglustat down-regulates sodium absorption in homozygous F508del-CFTR mice and human nasal cell (Abstract number 114). Pediatr PulmonolSuppl. 29:247.
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Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
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doi:10.1124/jpet.107.135582.
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ABBREVIATIONS: CF, cystic fibrosis; CFTR, CF transmembrane conductance regulator; F508del, deletion of phenylalanine at 508 position of CFTR protein; ER, endoplasmic reticulum; ENaC, epithelial sodium channel; miglustat, n-butyldeoxynojyrimicin; Isc, short-circuit current; PBS, phosphate-buffered saline; CFTRinh-172, 3-[(3-trifluoromethyl)phenyl]-5-[(4-carboxyphenyl)methylene]-2-thioxo-4-thiazolidinone; DMSO, dimethylsulfoxide; fsk, forskolin; Gst, genistein.
- Received December 18, 2007.
- Accepted February 27, 2008.
- The American Society for Pharmacology and Experimental Therapeutics
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