The lungs play an important role in producing blood. Until now it was thought that lungs were only responsible for breathing and the bone marrow was thought to be responsible for blood production.
According to a new research by the University of California, San Francisco has noticed that most of the platelets are mostly produced in the lungs and not inside the bone marrow. The study was carried out on mice and it says that the lungs have a reservoir of blood stem cells that act as a backup, in case the bone marrow runs dry.
The study has been published in the journal Nature.
Lungs helpful in blood production
Megakaryocytes are the cells helpful for the production of platelets. As they have been found in lung tissue before, it was thought that they primarily live and carry out their platelets-producing process inside the bone marrow.
The research noticed the new function of lungs while they were imaging the lungs of living mice in order to determine the way in which the platelets circulate through the lungs by interacting with the immune system.
“When we noticed this massive population of megakaryocytes that seemed to be living in the lung, we anticipated we had to conduct a follow-up study,” stated Emma Lefrançais, co-first author of the study.
After close inspection, the team noticed that the megakaryocytes in the lungs were producing more than 10 million platelets per hour, this number estimates for more than a half of the total amount of platelets generated by a mouse. These platelets seem to be fed by megakaryocyte progenitor cells, along with the blood stem cells which are present outside of the lung vasculature.
As part of the study, the team of scientists used video microscopy methods to examine the population of platelets in the lung area in a better way.
“These findings identify the lungs as a primary source of terminal platelet production and an organ with significant hematopoietic potential,” stated the research.
Lungs assist the bone marrow in producing blood
The lungs are responsible for massive part of blood production and working together with the bone marrow in order to do so. In order to understand how the stem cells are carried from one place to another, the researchers transplanted lungs from normal animals into mice whose megakaryocytes were fluorescent.
Concisely after the transplant, the “normal” lungs began to show glowing spots, which revealed that megakaryocytes are only transported into the lungs and they are born inside the bone marrow.