Thiazolidinone CFTR inhibitor identified by high-throughput screening blocks cholera toxin-induced intestinal fluid secretion.
Secretory diarrhea is the leading cause of infant death in developing countries and a major cause of morbidity in adults. The cystic fibrosis transmembrane conductance regulator (CFTR) protein is required for fluid secretion in the intestine and airways and, when defective, causes the lethal genetic disease cystic fibrosis. We screened 50,000 chemically diverse compounds for inhibition of cAMP/flavone-stimulated Cl(-) transport in epithelial cells expressing CFTR. Six CFTR inhibitors of the 2-thioxo-4-thiazolidinone chemical class were identified. The most potent compound discovered by screening of structural analogs, CFTR(inh)-172, reversibly inhibited CFTR short-circuit current in less than 2 minutes in a voltage-independent manner with K(I) approximately 300 nM. CFTR(inh)-172 was nontoxic at high concentrations in cell culture and mouse models. At concentrations fully inhibiting CFTR, CFTR(inh)-172 did not prevent elevation of cellular cAMP or inhibit non-CFTR Cl(-) channels, multidrug resistance protein-1 (MDR-1), ATP-sensitive K(+) channels, or a series of other transporters. A single intraperitoneal injection of CFTR(inh)-172 (250 micro g/kg) in mice reduced by more than 90% cholera toxin-induced fluid secretion in the small intestine over 6 hours. Thiazolidinone CFTR inhibitors may be useful in developing large-animal models of cystic fibrosis and in reducing intestinal fluid loss in cholera and other secretory diarrheas.
Ma
Tonghui
T
Department of Medicine, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California 94143-0521, USA.
Thiagarajah
Jay R
JR
Yang
Hong
H
Sonawane
Nitin D
ND
Folli
Chiara
C
Galietta
Luis J V
LJ
Verkman
A S
AS
D019943:Amino Acid Substitution; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002772:Cholera Toxin / Q000633:toxicity*; D005576:Colforsin / Q000494:pharmacology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000235:genetics; D003967:Diarrhea / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D051379:Mice; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D016297:Mutagenesis, Site-Directed; D018408:Patch-Clamp Techniques; D051381:Rats; D011916:Rats, Inbred F344; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors; D013844:Thiazoles / Q000494:pharmacology*
C505032:CFTR protein, human; D011994:Recombinant Proteins; D013844:Thiazoles; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D005576:Colforsin; D002772:Cholera Toxin