Researchers at the University of Pennsylvania have discovered a new type of cell in the human lung. Named respiratory airway secretory cells (RASCs), they seem to play a role in regenerating other cells and could be a target for new treatments for certain lung diseases.
The team made the discovery while studying the gene activity of lung cells from human donors. RASCs were found to be located in distal airway branches, where they produce proteins that form the fluid that lines the airways.
On closer inspection, the researchers discovered a connection to what are called AT2 cells, which function like stem cells for the alveoli, the air sacs of the lungs. RASCs, it seems, can differentiate into AT2 cells, which in turn differentiate into the functional cells of the alveoli. Intriguingly, RASCs are not found in the lung cells of mice, highlighting some of the shortcomings of animal models of disease and treatment.
This find could have implications for common lung diseases like chronic obstructive pulmonary disease (COPD). This condition, most often triggered by smoking, is marked by damage to the alveoli, which affects airflow through a patient’s lungs. AT2 cells are also known to become dysfunctional thanks to COPD.
But the team found that the problems could begin upstream. In samples from people with COPD and past smokers who don’t have the condition, the researchers found many AT2 cells with abnormalities that suggested issues stemming from RASCs not differentiating into AT2 cells properly. This could make RASCs an intriguing new target for treating lung diseases like COPD.
“COPD is a devastating and common disease, yet we really don’t understand the cellular biology of why or how some patients develop it,” said Maria Basil, first author of the study. “Identifying new cell types, in particular new progenitor cells, that are injured in COPD could really accelerate the development of new treatments.”
The research was published in the journal Nature.
Source: University of Pennsylvania
