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Scientists have discovered a whole new type of cell hiding in the delicate, branched passages of the human lung. The newly discovered cells are Respiratory system New studies show that it may even function properly and stimulate new treatments to reverse the effects of certain smoking-related illnesses.
Cells known as respiratory airway secretory (RAS) cells are found in small branched passages known as bronchioles. The bronchioles have alveoli, small air sacs that exchange oxygen. carbon Carbon dioxide with blood flow.The new RAS cell looks like this Stem cells — “Blank canvas” cells that can differentiate into other types of cells in the body — damaged alveolar cells can be repaired and converted into new cells.
Researchers discovered RAS cells after becoming increasingly dissatisfied with the limitations of relying on them. lung of mouse As a model of the human respiratory system. However, because of the specific differences between the two, scientists are having a hard time bridging the gap in knowledge about the human lung. To better understand these differences at the cellular level, the team took lung tissue samples from healthy human donors and analyzed the genes in individual cells. This reveals previously unknown RAS cells.
“It has long been known that the airways in the human lungs differ from those in mice,” senior author Edward Morissy, a professor at the University of Pennsylvania’s Perelman School of Medicine, who specializes in the respiratory system, told Live Science. rice field. .. “But it’s only recently that new technologies have allowed us to sample and identify unique cell types.”
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The team also discovered ferret RAS cells. The ferret’s respiratory system is more like the human respiratory system than the mouse. As a result, researchers believe that most mammals of the same size or larger are likely to have RAS cells in their lungs, Morrisey said.
RAS cells perform two major functions in the lungs. First, it secretes molecules that maintain fluid lining along the bronchioles, preventing small airways from collapsing and helping to maximize lung efficiency. Second, they can function as progenitor cells for alveolar type 2 (AT2) cells. This is a special type of alveoli that secretes chemicals that are partially used to repair other damaged alveoli. (Progenitor cells are cells that have the ability to differentiate into different types of cells, much like stem cells differentiate into other cells.)
“RAS cells are what we call common progenitor cells, which means that RAS cells act as both progenitor cells and play an important functional role in maintaining airway health.” Moricy said. He added that this means that RAS cells play an important role in maintaining a healthy lung.
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Researchers believe that RAS cells may play an important role in smoking-related disorders such as chronic obstructive pulmonary disease (“COPD). COPD is the result of inflammation of the airways in the lungs, which can be caused by smoking and, in some cases, by air pollution. Mayo Clinic (Opens in a new tab).. Inflammation of the airways makes it difficult for the lungs to get enough oxygen properly. As a result, COPD presents with symptoms similar to asthma. COPD can also cause emphysema, which permanently destroys the alveoli, and chronic bronchitis, a long-term severe cough, usually with excessive sputum. According to the report, more than 3 million people worldwide die from COPD each year. World Health Organization (Opens in a new tab)..
Theoretically, RAS cells should prevent or at least mitigate the effects of COPD by repairing damaged alveoli. However, researchers believe that smoking can damage or completely destroy new cells, leading to the development of diseases such as COPD.
Patients with COPD are often prescribed anti-inflammatory drugs and oxygen therapy to relieve their symptoms. However, these are only temporary solutions and the lung damage cannot be undone. If researchers can take advantage of the regenerative properties of these cells, RAS cells could be used to improve treatment or treat COPD.
“It’s not yet clear if this finding could lead to potential treatments for COPD,” Morrisey said. “But COPD is a disease we know little about, so new insights should help the field begin to think about new therapeutic approaches that may lead to better treatment.”
The study was published online in the journal on March 30 Nature (Opens in a new tab)..
Originally published on Live Science.
