First Author | Zdebik AA | Year | 2004 |
Journal | J Biol Chem | Volume | 279 |
Issue | 21 | Pages | 22276-83 |
PubMed ID | 15007059 | Mgi Jnum | J:89831 |
Mgi Id | MGI:3041726 | Doi | 10.1074/jbc.M309899200 |
Citation | Zdebik AA, et al. (2004) Additional disruption of the ClC-2 Cl(-) channel does not exacerbate the cystic fibrosis phenotype of cystic fibrosis transmembrane conductance regulator mouse models. J Biol Chem 279(21):22276-83 |
abstractText | Cystic fibrosis is a fatal inherited disease that is caused by mutations in the gene encoding a cAMP-activated chloride channel, the cystic fibrosis transmembrane conductance regulator (CFTR). It has been suggested that the cystic fibrosis phenotype might be modulated by the presence of other Cl(-) channels that are coexpressed with CFTR in some epithelial cells. Because the broadly expressed plasma membrane Cl(-) channel, ClC-2, is present in the tissues whose function is compromised in cystic fibrosis, we generated mice with a disruption of both Cl(-) channel genes. No morphological changes in their intestine, lung, or pancreas, tissues affected by cystic fibrosis, were observed in these mice. The mortality was not increased over that observed with a complete lack of functional CFTR. Surprisingly, mice expressing mutant CFTR (deletion of phenylalanine 508), survived longer when ClC-2 was disrupted additionally. Currents across colonic epithelia were investigated in Ussing chamber experiments. The disruption of ClC-2, in addition to CFTR, did not decrease Cl(-) secretion. Colon expressing wild-type CFTR even secreted more Cl(-) when ClC-2 was disrupted, although CFTR transcript levels were unchanged. It is concluded that ClC-2 is unlikely to be a candidate rescue channel in cystic fibrosis. Our data are consistent with a model in which ClC-2 is located in the basolateral membrane. |