A team of researchers from the Perelman School of Medicine at the University of Pennsylvania (USA) has identified a new lineage of secretory cells that were hidden in human lungs and, as the experts explain in their study published in the journal Nature, have a fundamental role in maintaining the gas exchange section and it is altered in chronic lung disease.
In this part of the body, these new cells, called airway secretory cells (RASC), appear to play an important role in regenerating other cells that are essential for the normal function of the alveoli.
The scientists made the discovery while studying the genetic activity of lung cells from human donors. They found that airway secretory cells were located in the distal branches of the airways, where they produce proteins that make up the fluid that lines the very airways involved in breathing.
Hidden within the delicate branching tubes of the human lungs
The newly discovered cell plays a crucial role in keeping the respiratory system functioning intact. These cells are found in small branching tubes known as bronchioles; they are very similar to stem cells : they are capable of repairing damaged cells in the alveoli (the air sacs of the lungs) and transforming them into new ones.
To identify them, the researchers took lung tissue samples from healthy human donors and analyzed the genes within individual cells , resulting in the previously unknown cells being found (although they also found them in ferrets, whose respiratory system is more similar that of humans than that of mice, so scientists suspect that it is likely that most mammals of equal or larger size have these types of cells in their lungs).
The new cells could represent a new field of study for new treatments for certain lung diseases , as the researchers found evidence that cigarette smoking and common smoking-related chronic obstructive pulmonary disease (COPD) can impair the regenerative functions of these cells. , suggesting that correcting this interruption could be a good way to treat COPD.
“COPD is a common and devastating disease, but we don’t really understand the cell biology of why or how some patients develop it,” said Maria Basil, a researcher in the Department of Medicine and the Penn-CHOP Institute of Pulmonary Biology in the College of Perelman Medicine of the University of Pennsylvania. “Identifying new cell types, particularly new progenitor cells, that are injured in COPD could really accelerate the development of new treatments.”
COPD is the result of inflammation of the airways within the lungs, which can be caused by smoking and occasionally air pollution, according to the Mayo Clinic. Inflammation of the airways makes it difficult for the lungs to properly absorb enough oxygen; as a result, COPD has symptoms similar to asthma. For this reason, experts suggest that cells from this lineage could potentially be used to improve treatments or even cure COPD in the future, if researchers can properly harness the regenerative properties of these cells.
Referencia: M.C. Basil et al. Human distal airways contain a multipotent secretory cell that can regenerate alveoli. Nature, published online March 30, 2022; doi: 10.1038/s41586-022-04552-0