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: Joana Almaça, Diana Faria, Marisa Sousa, Inna Uliyakina, Christian Conrad, Lalida Sirianant, Luka A Clarke, José Paulo Martins, Miguel Santos, Jean-Karim Heriché, Wolfgang Huber, Rainer Schreiber, Rainer Pepperkok, Karl Kunzelmann, Margarida D Amaral
• Journal: Cell (Cell) Vol. 154 Issue 6 Pg. 1390-400 (Sep 12 2013) ISSN: 1097-4172 [Electronic] United States
• PMID: 24034256 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Elsevier Inc. All rights reserved.

Chemical References

• Epithelial Sodium Channels
• RNA, Small Interfering

Topics

• Cell Line
• Cells, Cultured
• Cystic Fibrosis (drug therapy)
• Epithelial Sodium Channels (metabolism)
• Humans
• Lung (cytology, metabolism)
• Molecular Targeted Therapy
• RNA, Small Interfering