In people with cystic fibrosis, mucus is dehydrated, becoming so thick and sticky that the cilia are unable to propel mucus out of the lungs. As a result, the mucus clogs the

In people with CF,
This animation depicts how mucus builds up in the lungs of people with cystic fibrosis.
Researchers believe another protein channel on the surface of the cell adds to this hydration problem. This channel, known as the epithelial sodium channel (ENaC), absorbs sodium (another component of salt) into the cell, which also helps to maintain the correct balance of salt and fluids on the cell surface. In people with CF, researchers think the sodium channel is hyperactive and takes in too much salt. Thus, this overactive channel contributes to the dehydration problem in the airway.
To advance the development of new treatments, scientists are studying how
- How mucus affects the airway
- Why mucus is abnormal in CF
- Where mucus is most important
- How the properties of mucus affect its structure
- Why CF mucus is more prone to infection
Scientists also are conducting research on how much liquid covers the cells lining the
Researchers are evaluating drugs for their effectiveness in preventing, thinning, and breaking up the
By restoring function to the
Researchers also are working on drugs that are mutation-agnostic, which means they can help all people with CF regardless of their mutations. One such drug would prevent mucus from becoming dehydrated, inhibiting the hyperactive ENaC to enable more salt on the cell surface. The salt would then attract fluids, hydrating the mucus. Several ENaC inhibitors are under development in clinical trials.
In this video, Scott H. Donaldson, M.D., associate professor of medicine and director of the adult CF center at the University of North Carolina, talks about ENaC inhibitors and other approaches being explored to improve
For more information on current treatments, visit Medications.