title: Rescue of the mutant CFTR chloride channel by pharmacological correctors and low temperature analyzed by gene expression profiling.
abstract: The F508del mutation, the most frequent in cystic fibrosis (CF), impairs the maturation of the CFTR chloride channel. The F508del defect can be partially overcome at low temperature (27°C) or with pharmacological correctors. However, the efficacy of correctors on the mutant protein appears to be dependent on the cell expression system. We have used a bronchial epithelial cell line, CFBE41o-, to determine the efficacy of various known treatments and to discover new correctors. Compared with other cell types, CFBE41o- shows the largest response to low temperature and the lowest one to correctors such as corr-4a and VRT-325. A screening of a small-molecule library identified 9-aminoacridine and ciclopirox, which were significantly more effective than corr-4a and VRT-325. Analysis with microarrays revealed that 9-aminoacridine, ciclopirox, and low temperature, in contrast to corr-4a, cause a profound change in cell transcriptome. These data suggest that 9-aminoacridine and ciclopirox act on F508del-CFTR maturation as proteostasis regulators, a mechanism already proposed for the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA). However, we found that 9-aminoacridine, ciclopirox, and SAHA, in contrast to corr-4a, VRT-325, and low temperature, do not increase chloride secretion in primary bronchial epithelial cells from CF patients. These conflicting data appeared to be correlated with different gene expression signatures generated by these treatments in the cell line and in primary bronchial epithelial cells. Our results suggest that F508del-CFTR correctors acting by altering the cell transcriptome may be particularly active in heterologous expression systems but markedly less effective in native epithelial cells.
authors.affiliation: Laboratory of Molecular Genetics, Istituto Giannina Gaslini, Genoa, Italy.
authors.forename: Elvira
authors.initials: E
authors.lastname: Sondo
authors.forename: Valeria
authors.initials: V
authors.lastname: Tomati
authors.forename: Emanuela
authors.initials: E
authors.lastname: Caci
authors.forename: Alessia Isabella
authors.initials: AI
authors.lastname: Esposito
authors.forename: Ulrich
authors.initials: U
authors.lastname: Pfeffer
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Pedemonte
authors.forename: Luis J V
authors.initials: LJ
authors.lastname: Galietta
mesh_terms: D000585:Aminacrine; D001426:Bacterial Proteins; D001549:Benzamides; D002460:Cell Line; D002462:Cell Membrane; D002712:Chlorides / Q000378:metabolism; D000077768:Ciclopirox; D003080:Cold Temperature; D003550:Cystic Fibrosis / Q000235:genetics / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics* / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D006877:Hydroxamic Acids; D008164:Luminescent Proteins; D009154:Mutation; D010879:Piperazines; D021381:Protein Transport / Q000235:genetics / Q000502:physiology; D011728:Pyridones; D011799:Quinazolines; D013844:Thiazoles; D000077337:Vorinostat
chemical_list: C507255:4-cyclohexyloxy-2-(1-(4-(4-methoxy-benzenesulfonyl)piperazin-1-yl)ethyl)quinazoline; D001426:Bacterial Proteins; D001549:Benzamides; C505032:CFTR protein, human; D002712:Chlorides; D006877:Hydroxamic Acids; D008164:Luminescent Proteins; C561871:N-(2-5-chloro-2-methoxyphenylamino)4'-methyl(4,5''bithiazolyl-2'-yl)benzamide; D010879:Piperazines; D011728:Pyridones; D011799:Quinazolines; D013844:Thiazoles; C054562:yellow fluorescent protein, Bacteria; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D000077768:Ciclopirox; D000077337:Vorinostat; D000585:Aminacrine