Differential expression of ORCC and CFTR induced by low temperature in CF airway epithelial cells.
When nonepithelial cell types expressing the delta F508-cystic fibrosis transmembrane conductance regulator (CFTR) mutation are grown at reduced temperatures, the mutant protein can be properly processed. The effect of low temperatures on Cl- channel activity in airway epithelial cells that endogenously express the delta F508-CFTR mutation has not been investigated. Therefore, we examined the effect of incubation temperature on both CFTR and outwardly rectifying Cl- channel (ORCC) activity in normal, in cystic fibrosis (CF)-affected, and in wild-type CFTR-complemented CF airway epithelia with use of a combination of inside-out and whole cell patch-clamp recording, 36Cl- efflux assays, and immunocytochemistry. We report that incubation of CF-affected airway epithelial cells at 25-27 degrees C is associated with the appearance of a protein kinase A-stimulated CFTR-like Cl- conductance. In addition to the appearance of CFTR Cl- channel activity, there is, however, a decrease in the number of active ORCC when cells are grown at 25-27 degrees C, suggesting that the decrease in incubation temperature may be associated with multiple alterations in ion channel expression and/or regulation in airway epithelial cells.
Egan
M E
ME
Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520-8064.
Schwiebert
E M
EM
Guggino
W B
WB
D001980:Bronchi / Q000378:metabolism* / Q000473:pathology; D002460:Cell Line; D018118:Chloride Channels / Q000378:metabolism* / Q000502:physiology; D000242:Cyclic AMP / Q000494:pharmacology; D003550:Cystic Fibrosis / Q000378:metabolism* / Q000473:pathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D004553:Electric Conductivity; D004594:Electrophysiology; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000378:metabolism*; D012016:Reference Values; D013696:Temperature; D014018:Tissue Distribution
C505032:CFTR protein, human; D018118:Chloride Channels; D008565:Membrane Proteins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D000242:Cyclic AMP