New cells discovered in the airway might hold the key to cystic fibrosis
Although it's a very well-studied disease, there's still no cure for cystic fibrosis. But we may be a step closer to finding new treatments, as two research teams are now reporting the discovery of a new type of cell in the airways. These rare cells seem to be where most activity of a certain gene is located, mutations of which are known to cause cystic fibrosis.
Cystic fibrosis is a common genetic disease that affects cells that produce fluids like mucus, sweat and digestive enzymes. In people who are affected, these fluids become too thick and begin to clog up vital tubes, leaving them with coughing fits, shortness of breath, digestive problems, and a drastically-reduced life expectancy.
Unfortunately, there's no current cure for cystic fibrosis, but treatment can help keep related infections at bay, improve patient comfort and increase life expectancy.
In order to discover better treatment options and perhaps even a potential cure, researchers in two separate studies aimed to collate an "atlas" of cells in the airway. Using single-cell sequencing technology, the researchers combed through tens of thousands of cells to build comprehensive catalogs of different cell types, including how common they are, where they are, and how they express genes.
That meticulous process revealed some previously unknown cell types, including some that the researchers have now named "pulmonary ionocytes." These cells make up about one percent of the total cells in the airways, and their gene expression was particularly interesting.
In the 1980s, mutations to a gene called cystic fibrosis transmembrane conductance regulator (CFTR) was discovered to play a key role in development of the disease. It was long thought that CFTR was expressed in common airway cells called ciliated cells, but the new study has revealed that the gene's activity is highly concentrated in the newly-discovered pulmonary ionocytes.
"As researchers work toward cures for cystic fibrosis, knowing you are looking at one percent of the cell population seems essential for any type of troubleshooting to improve a therapy or develop new therapies," says Allon Klein, co-corresponding author of one of the studies.
In one of the studies, the team disrupted a molecular process in the pulmonary ionocytes of mice, and found that the animals developed denser mucus – a key problem associated with cystic fibrosis. With the link firmly in place, these cells could be an enticing new target for therapies for the disease, such as finding ways to increase the number of pulmonary ionocytes in the airway, to boost levels of CFTR activity.