CFTR - "Different modes of activation of CFTR recorded on Nanion’s SyncroPatch 384PE"
SyncroPatch 384PE application note (5.7 MB)
Cystic Fibrosis (CF) is an autosomal recessive genetic disorder which affects a number of organs, in particular the lungs, pancreas and sweat glands. It is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator protein (CFTR). CFTR is a regulated epithelial chloride channel and mutations cause a reduction in activity of the channel via a variety of mechanisms. This results in defective electrolyte transport in airway epithelia and thereby, chronic lung infection and premature mortality. Therefore, compounds which increase activity of CFTR have therapeutic potential for treating CF. The CFTR protein is composed of 5 domains: there are 2 transmembrane (TM) domains, 2 nucleotidebinding domains (NBDs) and 1 regulatory domain (R). The TM domains form the pore of the channel, channel activity is determined by phosphorylation of the R domain and gating is controlled by hydrolysis of ATP at the NBD. CFTR is activated via a number of reagents including internal fluoride, cAMP and external forskolin. Here we show activation of CFTR expressed in CHO cells on the SyncroPatch 384PE by internal perfusion of F- or external application of forskolin. The current was blocked with the specific blocker, inh-172 with an IC50 in good agreement with the literature. In addition, CFTR activated by internal cAMP was potentiated by VX-770. Using F- -free internal solution and activation by submaximal cAMP or forskolin, potentiators of CFTR can be investigated as potential therapeutics to treat CF.