Whenever we consider tissue regeneration, we typically consider stem cells as well as their ability to develop into an array of different cell types.
However, a group of scientists from Duke University and the University of Pennsylvania show that certain cells in the lungs are able to give rise to other lung cell types, according to a new study within the journal Nature Communications.
“It’s as if the lung cells can regenerate from one another as needed to correct missing tissue, suggesting that there\’s a lot more flexibility in the system than we have previously appreciated,” said study author Dr. Jon Epstein, chair of the department of Cell and Developmental Biology at Penn. “These aren’t classic stem cells that we see regenerating the lung. They\’re mature lung cells that awaken in reaction to injury.\”
\”We would like to learn the way the lung regenerates so that we are able to stimulate the procedure in situations where it is insufficient, for example in patients with COPD (chronic obstructive pulmonary disease),\” he added.
There are two kinds of cells in mid-air sacs from the lung referred to as alveoli. Long, slender Type 1 cells are where inhaled gases are exchanged. Type 2 cells release surfactant, a soapy compound which helps in keeping airways open. Sometimes, premature babies have to be given surfactant to assist them with breathing.
In the study, they used mouse models to locate that both of these kinds of cells come from a typical precursor stem cell in the embryo. Next, the researchers used other mouse models involving part of the lung that was removed for cell cultures to look at the plasticity of cell types throughout lung regeneration. They saw that Type 1 cells can provide rise to Type 2 cells, and vice-versa.
Researchers from Duke had previously found that Type 2 cells can differentiate into gas-exchanging Type 1 cells. However, the capacity of Type I cells also to differentiate was not previously reported.
“We found that Type 1 cells give rise to the kind 2 cells over about three weeks in various types of regeneration,\” said study author Dr. Rajan Jain, a cardiologist?at Duke. \”We saw new cells growing back into these new regions of the lung. It’s as if the lung knows it must re-grow and may call into action some Type 1 cells to help in that process.”
The study team noted that they\’re applying their findings to studies of cells in the intestine and skin. I was told that they will be investigating other lung conditions where alveoli cannot absorb enough oxygen.