Friday, 04 October 2013 20:14

New in vitro approach allows research on cystic fibrosis Featured

Scientists from Regensburg together with collegues from Heidelberg and Lisboa have found a new approach against cystic fibrosis. For their investigations they used airway epithelial cells from CF patients.

The aim of this study was to perform a loss-of-function screen mainly designed to globally identify regulators of ENaC traffic / function, with the ultimate goal of finding putative drug targets for CF.

Dysfunction of ENaC, the epithelial sodium channel that regulates salt and water reabsorption in epithelia, causes several human diseases, including cystic fibrosis (CF). For their research the scientists used airway epithelial cells from CF patients.

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 highcontent live-cell microscopy and siRNAs in human airway epithelial cells.
The scientists isolated airway epithelial cells from lungs of CF patients and grew them as highly differentiated polarized cultures under ALI conditions.

They screened over 6,000 genes and identified over 1,500 candidates, which they 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 that a special receptor called CNTFR funcionate as an ENaC modulator. The inhibition of (diacylglycerol kinase) can 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.

The fundings are published in the journal Cell (2013,  Bd. 154, S.1390):
Almac¸J., Faria, D., Sousa, M., Uliyakina, I., Conrad, C., Sirianant, L., Clarke, L. A., Martins, J. P., Santos, M., Heriche, J.-K., Huber, W., Schreiber, R., Pepperkok, R., Kunzelmann, K. & Amaral, M. D. (2013): High-Content siRNA Screen Reveals Global ENaC Regulators and Potential Cystic Fibrosis Therapy Targets. Cell 154: 1390-1400.