title: Activation of endogenous deltaF508 cystic fibrosis transmembrane conductance regulator by phosphodiesterase inhibition.
abstract: Many heterologously expressed mutants of the cystic fibrosis transmembrane conductance regulator (CFTR) exhibit residual chloride channel activity that can be stimulated by agonists of the adenylate cyclase/protein kinase A pathway. Because of clinical implications for cystic fibrosis of activating mutants in vivo, we are investigating whether deltaF508, the most common disease-associated CFTR mutation, can be activated in airway epithelial cells. We have found that, 36Cl- efflux can be stimulated 19-61% above baseline by beta-adrenoreceptor agonists and cGI-phosphodiesterase inhibitors in transformed nasal polyp (CF-T43) cells homozygous for the deltaF508 mutation. The increase in 36Cl- permeability is diminished by protein kinase A inhibitors and is not mediated by an increase in intracellular calcium concentrations. Preincubation of CF-T43 cells with CFTR anti-sense oligonucleotides prevented an increase in 36Cl- efflux in response to beta-agonist and phosphodiesterase inhibitor. Primary cells isolated from CF nasal polyps gave similar results. These data indicate that endogenous levels of deltaF508 protein can be stimulated to increase 36Cl- permeability in airway epithelial cells.
authors: Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio 44106-4948, USA.
authors: T J
authors: TJ
authors: Kelley
authors: L
authors: L
authors: Al-Nakkash
authors: C U
authors: CU
authors: Cotton
authors: M L
authors: ML
authors: Drumm
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000420:Albuterol / Q000494:pharmacology; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D002712:Chlorides / Q000378:metabolism*; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D003550:Cystic Fibrosis / Q000503:physiopathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism*; D004357:Drug Synergism; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004848:Epithelium; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D020105:Milrinone; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D011728:Pyridones / Q000494:pharmacology*; D013873:Thionucleotides / Q000494:pharmacology
chemical_list: D000318:Adrenergic beta-Agonists; C505032:CFTR protein, human; D002712:Chlorides; D004791:Enzyme Inhibitors; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D010726:Phosphodiesterase Inhibitors; D011728:Pyridones; D013873:Thionucleotides; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; C016957:adenosine-3',5'-cyclic phosphorothioate; D004533:Egtazic Acid; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D020105:Milrinone; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D007545:Isoproterenol; D000420:Albuterol; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine