Activation of endogenous deltaF508 cystic fibrosis transmembrane conductance regulator by phosphodiesterase inhibition.
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.
Kelley
T J
TJ
Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio 44106-4948, USA.
Al-Nakkash
L
L
Cotton
C U
CU
Drumm
M L
ML
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
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