Chronic asthma could be caused by cell overcrowding in the airways
These images show how an asthma attack can affect the airways. In the left image, mouse epithelial tissue (greenish-yellow) lining the lung is fully open but collapses (right) once treated with a drug known to narrow the airways. The constriction can lead to the tissue jettisoning epithelial cells, new research shows.
Despite a wealth of available treatments to control the symptoms of chronic asthma, the lung disease has no cure. The discovery of an unexpected cause of asthma could change that.
A glitch in the mechanical process that drives normal turnover of epithelial cells lining the lungs could be to blame, researchers report in the April 5 Science. Better understanding of this physical force underpinning chronic asthma attacks might lead to new ways of combating the disease.
The mechanical process that drives epithelial lung cell turnover is called cell extrusion. It goes something like this: Epithelial cells in the lung lining replicate, and as new cells populate the tissue, things get crowded and pressure between the cells increases. Cells sense this crowding and initiate a process that ejects weaker cells from the layer, forcing them to die off. The process maintains a healthy epithelial lining in the airways.
