title: High-content siRNA screen reveals global ENaC regulators and potential cystic fibrosis therapy targets.
abstract: Dysfunction of ENaC, the epithelial sodium channel that regulates salt and water reabsorption in epithelia, causes several human diseases, including cystic fibrosis (CF). To develop a global understanding of molecular regulators of ENaC traffic/function and to identify of candidate CF drug targets, we performed a large-scale screen combining high-content live-cell microscopy and siRNAs in human airway epithelial cells. Screening over 6,000 genes identified over 1,500 candidates, evenly divided between channel inhibitors and activators. Genes in the phosphatidylinositol pathway were enriched on the primary candidate list, and these, along with other ENaC activators, were examined further with secondary siRNA validation. Subsequent detailed investigation revealed ciliary neurotrophic factor receptor (CNTFR) as an ENaC modulator and showed that inhibition of (diacylglycerol kinase, iota) DGKι, a protein involved in PiP2 metabolism, downgrades ENaC activity, leading to normalization of both Na+ and fluid absorption in CF airways to non-CF levels in primary human lung cells from CF patients.
authors.affiliation: University of Lisboa, Faculty of Sciences, BioFIG - Centre for Biodiversity, Functional and Integrative Genomics, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Almaça
authors.forename: Diana
authors.initials: D
authors.lastname: Faria
authors.forename: Marisa
authors.initials: M
authors.lastname: Sousa
authors.forename: Inna
authors.initials: I
authors.lastname: Uliyakina
authors.forename: Christian
authors.initials: C
authors.lastname: Conrad
authors.forename: Lalida
authors.initials: L
authors.lastname: Sirianant
authors.forename: Luka A
authors.initials: LA
authors.lastname: Clarke
authors.forename: José Paulo
authors.initials: JP
authors.lastname: Martins
authors.forename: Miguel
authors.initials: M
authors.lastname: Santos
authors.forename: Jean-Karim
authors.initials: JK
authors.lastname: Heriché
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Huber
authors.forename: Rainer
authors.initials: R
authors.lastname: Schreiber
authors.forename: Rainer
authors.initials: R
authors.lastname: Pepperkok
authors.forename: Karl
authors.initials: K
authors.lastname: Kunzelmann
authors.forename: Margarida D
authors.initials: MD
authors.lastname: Amaral
mesh_terms: D002460:Cell Line; D002478:Cells, Cultured; D003550:Cystic Fibrosis / Q000188:drug therapy*; D053503:Epithelial Sodium Channels / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000166:cytology / Q000378:metabolism; D058990:Molecular Targeted Therapy; D034741:RNA, Small Interfering
chemical_list: D053503:Epithelial Sodium Channels; D034741:RNA, Small Interfering