Scientists in this research discovered and identified the role of alveolar epithelial progenitor cells. They produce new air sacs in the mouse model and human lungs after injury. They can also be a potential target for revitalizing lung regeneration process.
Our lungs take in oxygen from the air and exhale carbon dioxide. Air sacs in our lungs can be damaged due to injury, disease or any viral infection. Damage to the lungs causes many complications and make it difficult to breathe. Lung tissue repairment is a slow and gradual process.
Scientists at the University of Pennsylvania conducted this research. NIH’s National Heart, Lung and Blood Institute supported this study. It is published in the journal “NATURE”.
The analysis of alveolar cells
Scientists compared the activity of alveolar cells in mice with lung injury to the mice with healthy lungs. This lung damage was caused by the influenza virus. They traced the cells that contained the known markers for alveolar type 2 cells. AT2 cells are those that produce surfactant.
Surfactant contributes towards protecting alveolar type 1 cells. AT1 cells are the gas exchanging cells in the lungs.
After a month of injury, these traced cells expanded and produced a large amount of both AT1 and AT2. These cells renewed themselves as well. After three months, observations showed that a large number of AT1 and AT2 were produced by injury-induced cells.
Scientists now call them alveolar epithelial progenitor (AEP) cells. Furthermore, using the information from gene and protein expression of AEP cells, they were able to isolate these cells. These cells were isolated from human lung tissue.
These cells were utilized to grow organoids (3d organ-like structure) in the laboratory. Further evaluation showed that these cells have molecular similarity with other species.
When we breathe in, air moves from our nostrils to the windpipe and finally into the lungs. After passing through bronchus and bronchial tubules, air reaches alveoli also known as air sacs. Oxygen passes from the thin walls of alveoli to capillaries surrounding them. On the other hand, carbon dioxide moves from the blood vessels to air sacs and is exhaled from nose or mouth. Any injury to these air sacs can result in troubled breathing.
Organoids in this research was able to show that alveolar epithelial progenitor cells are evolutionarily conserved. They can be used as the potential targets in lung regeneration and can be used for various lung treatments.
There is a need for tissue regeneration after a severe injury or a trauma. Identification of these alveolar epithelial progenitor cells is a novel finding. These studies are the stepping stone towards future discoveries and help us to better understand the lung regeneration process. They also promote collaborations that bring the field closer to various new treatments of acute and chronic lung diseases.
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