Structural analog of sildenafil identified as a novel corrector of the F508del-CFTR trafficking defect.
The F508del mutation impairs trafficking of the cystic fibrosis transmembrane conductance regulator (CFTR) to the plasma membrane and results in a partially functional chloride channel that is retained in the endoplasmic reticulum and degraded. We recently used a novel high-throughput screening (HTS) assay to identify small-molecule correctors of F508del CFTR trafficking and found several classes of hits in a screen of 2000 compounds (Carlile et al., 2007). In the present study, we have extended the screen to 42,000 compounds and confirmed sildenafil as a corrector using this assay. We evaluated structural analogs of sildenafil and found that one such molecule called KM11060 (7-chloro-4-{4-[(4-chlorophenyl) sulfonyl] piperazino}quinoline) was surprisingly potent. It partially restored F508del trafficking and increased maturation significantly when baby hamster kidney (BHK) cells were treated with 10 nM for 24 h or 10 muM for 2 h. Partial correction was confirmed by the appearance of mature CFTR in Western blots and by using halide flux, patch-clamp, and short-circuit current measurements in unpolarized BHK cells, monolayers of human airway epithelial cells (CFBE41o(-)), and intestines isolated from F508del-CFTR mice (Cftr(tm1Eur)) treated ex vivo. Small-molecule correctors such as KM11060 may serve as useful pharmacological tools in studies of the F508del-CFTR processing defect and in the development of cystic fibrosis therapeutics.
Robert
Renaud
R
McIntyre Building, Physiology Department, 3655 Promenade Sir William Osler, Montreal, Quebec, H3G 1Y6, Canada. renaud.robert@mcgill.ca
Carlile
Graeme W
GW
Pavel
Catalin
C
Liu
Na
N
Anjos
Suzana M
SM
Liao
Jie
J
Luo
Yishan
Y
Zhang
Donglei
D
Thomas
David Y
DY
Hanrahan
John W
JW
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D051379:Mice; D010879:Piperazines / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D021381:Protein Transport / Q000235:genetics; D011687:Purines / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism; D017384:Sequence Deletion; D000068677:Sildenafil Citrate; D013329:Structure-Activity Relationship; D013450:Sulfones / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*
D010879:Piperazines; D011687:Purines; D013450:Sulfones; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D000068677:Sildenafil Citrate