Small-molecule screen identifies inhibitors of a human intestinal calcium-activated chloride channel

Ricardo De La Fuente, Wan Namkung, Aaron Mills, Alan S. Verkman

Research output: Contribution to journalArticle

122 Citations (Scopus)

Abstract

Calcium-activated chloride channels (CaCCs) are widely expressed in mammalian tissues, including intestinal epithelia, where they facilitate fluid secretion. Potent, selective CaCC inhibitors have not been available. We established a high-throughput screen for identification of inhibitors of a human intestinal CaCC based on inhibition of ATP/carbachol-stimulated iodide influx in HT-29 cells after lentiviral infection with the yellow fluorescent halide-sensing protein YFP-H148Q/I152L. Screening of 50,000 diverse, drug-like compounds yielded six classes of putative CaCC inhibitors, two of which, 3-acyl-2-aminothiophenes and 5-aryl-2-aminothiazoles, inhibited by >95% iodide influx in HT-29 cells in response to multiple calcium-elevating agonists, including thapsigargin, without inhibition of calcium elevation, calcium-calmodulin kinase II activation, or cystic fibrosis transmembrane conductance regulator chloride channels. These compounds also inhibited calcium-dependent chloride secretion in T84 human intestinal epithelial cells. Patch-clamp analysis indicated inhibition of CaCC gating, which, together with the calcium-calmodulin data, suggests that the inhibitors target the CaCC directly. Structure-activity relationships were established from analysis of more than 1800 analogs, with IC50 values of the best analogs down to ∼1 μM. Small-molecule CaCC inhibitors may be useful in pharmacological dissection of CaCC functions and in reducing intestinal fluid losses in CaCC-mediated secretory diarrheas.

Original languageEnglish
Pages (from-to)758-768
Number of pages11
JournalMolecular Pharmacology
Volume73
Issue number3
DOIs
Publication statusPublished - 2008 Mar 1

Fingerprint

Chloride Channels
Calcium
HT29 Cells
Iodides
Fluids and Secretions
Cystic Fibrosis Transmembrane Conductance Regulator
Calcium Chloride
Calcium-Calmodulin-Dependent Protein Kinases
Thapsigargin
Carbachol
Calmodulin
Intestinal Mucosa
Structure-Activity Relationship
Inhibitory Concentration 50
Dissection
Diarrhea
Adenosine Triphosphate
Epithelial Cells
Pharmacology

All Science Journal Classification (ASJC) codes

  • Pharmacology

Cite this

De La Fuente, Ricardo ; Namkung, Wan ; Mills, Aaron ; Verkman, Alan S. / Small-molecule screen identifies inhibitors of a human intestinal calcium-activated chloride channel. In: Molecular Pharmacology. 2008 ; Vol. 73, No. 3. pp. 758-768.
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Small-molecule screen identifies inhibitors of a human intestinal calcium-activated chloride channel. / De La Fuente, Ricardo; Namkung, Wan; Mills, Aaron; Verkman, Alan S.

In: Molecular Pharmacology, Vol. 73, No. 3, 01.03.2008, p. 758-768.

Research output: Contribution to journalArticle

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