title: Spiperone, identified through compound screening, activates calcium-dependent chloride secretion in the airway.
abstract: Cystic fibrosis (CF) is caused by mutations in the gene producing the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR functions as a Cl(-) channel. Its dysfunction limits Cl(-) secretion and enhances Na+ absorption, leading to viscous mucus in the airway. Ca2+-activated Cl(-) channels (CaCCs) are coexpressed with CFTR in the airway surface epithelia. Increases in cytosolic Ca(2+) activate the epithelial CaCCs, which provides an alternative Cl(-) secretory pathway in CF. We developed a screening assay and screened a library for compounds that could enhance cytoplasmic Ca2+, activate the CaCC, and increase Cl(-) secretion. We found that spiperone, a known antipsychotic drug, is a potent intracellular Ca2+ enhancer and demonstrated that it stimulates intracellular Ca2+, not by acting in its well-known role as an antagonist of serotonin 5-HT2 or dopamine D2 receptors, but through a protein tyrosine kinase-coupled phospholipase C-dependent pathway. Spiperone activates CaCCs, which stimulates Cl(-) secretion in polarized human non-CF and CF airway epithelial cell monolayers in vitro and in CFTR-knockout mice in vivo. In conclusion, we have identified spiperone as a new therapeutic platform for correction of defective Cl(-) secretion in CF via a pathway independent of CFTR.
authors.affiliation: Department of Physiology, Johns Hopkins University School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA.
authors.forename: Lihua
authors.initials: L
authors.lastname: Liang
authors.forename: Kelvin
authors.initials: K
authors.lastname: MacDonald
authors.forename: Erik M
authors.initials: EM
authors.lastname: Schwiebert
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Zeitlin
authors.forename: William B
authors.initials: WB
authors.lastname: Guggino
mesh_terms: D000818:Animals; D001681:Biological Assay; D001980:Bronchi / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D016764:Cell Polarity; D018118:Chloride Channels / Q000187:drug effects* / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism*; D003550:Cystic Fibrosis / Q000188:drug therapy / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D051379:Mice; D018181:Mice, Inbred CFTR; D009297:Nasal Mucosa / Q000187:drug effects / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D019141:Respiratory System Agents / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D054852:Small Molecule Libraries; D013134:Spiperone / Q000494:pharmacology*; D013997:Time Factors; D014132:Trachea / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: C505032:CFTR protein, human; D018118:Chloride Channels; D002712:Chlorides; D019141:Respiratory System Agents; D054852:Small Molecule Libraries; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D013134:Spiperone; D011505:Protein-Tyrosine Kinases; D010738:Type C Phospholipases; D002118:Calcium