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Correction of G551D‐CFTR transport defect in epithelial monolayers by genistein but not by CPX or MPB‐07
Author(s) -
ZegarraMoran Olga,
Romio Leila,
Folli Chiara,
Caci Emanuela,
Becq Frederic,
Vierfond JeanMichel,
Mettey Yvette,
Cabrini Giulio,
Fanen Pascale,
Galietta Luis J V
Publication year - 2002
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0704882
Subject(s) - genistein , cystic fibrosis transmembrane conductance regulator , glibenclamide , chemistry , endocrinology , apical membrane , chloride channel , cyclic adenosine monophosphate , medicine , forskolin , transfection , wild type , microbiology and biotechnology , cystic fibrosis , biology , biochemistry , mutant , in vitro , receptor , membrane , diabetes mellitus , gene
This study compares the effect of three chemically unrelated cystic fibrosis transmembrane conductance regulator (CFTR) activators on epithelial cell monolayers expressing the G551D‐CFTR mutant. We measured Cl − transport as the amplitude of short‐circuit current in response to the membrane permeable cAMP analogue 8‐(4‐chlorophenylthio)adenosine‐3′‐5′‐cyclic monophosphate (CPT‐cAMP) alone or in combination with a CFTR opener. The correction of G551D‐CFTR defect was quantified by comparison with maximal activity elicited in cells expressing wild type CFTR. To this end we used Fisher rat thyroid (FRT) cells transfected with wild type or G551D CFTR, and primary cultures of human nasal epithelial cells. In both types of epithelia, cAMP caused activation of Cl − transport that was inhibited by glibenclamide and not by 4,4′‐diisothiocyanato‐stilbene‐2,2′‐disulfonic acid. After normalising for CFTR expression, the response of FRT‐G551D epithelia was 1% that of wild type monolayers. Addition of genistein (10–200 μ M ), but not of 8‐cyclopentyl‐1,3‐dipropylxanthine (CPX, 1–100 μ M ) or of the benzo[c]quinolizinium MPB‐07 (10–200 μ M ) to FRT‐G551D epithelia pre‐treated with cAMP, stimulated a sustained current that at maximal genistein concentration corresponded to 30% of the response of wild type epithelia. The genistein dose‐response curve was bell‐shaped due to inhibitory activity at the highest concentrations. The dose‐dependence in G551D cells was shifted with respect to wild type CFTR so that higher genistein concentrations were required to observe activation and inhibition, respectively. On human nasal epithelia the correction of G551D‐CFTR defective conductance obtained with genistein was 20% that of wild type. The impressive effect of genistein suggests that it might correct the Cl − transport defect on G551D patients.British Journal of Pharmacology (2002) 137 , 504–512. doi: 10.1038/sj.bjp.0704882