Lungs may play key role in blood production, doc says

To the researchers, this indicated that resident megakaryocyte progenitors in the transplanted lungs had become activated by the recipient mouse’s low platelet counts and had produced healthy megakaryocytes to restore proper platelet production.

Finally, the researchers tested whether lung hematopoietic progenitors were capable of multi-lineage bone marrow reconstitution.

They found that cells originating from transplanted lungs traveled to damaged bone marrow and contributed to the production of platelets and other blood cells, including neutrophils, B cells, and T cells.

The researchers said these experiments suggest the lungs play host to a variety of hematopoietic progenitors capable of reconstituting damaged bone marrow and restoring the production of many components of the blood.

“To our knowledge, this is the first description of blood progenitors resident in the lung, and it raises a lot of questions with clinical relevance for the millions of people who suffer from thrombocytopenia,” Dr Looney said.

In particular, the study suggests that researchers who have proposed treating platelet diseases with platelets produced from engineered megakaryocytes should look to the lungs as a resource for platelet production, Dr Looney noted.

The study also presents new avenues of research for stem cell biologists to explore how the bone marrow and lung collaborate to produce a healthy blood system through the mutual exchange of stem cells.

“These observations alter existing paradigms regarding blood cell formation, lung biology and disease, and transplantation,” said pulmonologist Guy A. Zimmerman, MD, who is associate chair of the Department of Internal Medicine at the University of Utah School of Medicine and was an independent reviewer of this study for Nature.

“The findings have direct clinical relevance and provide a rich group of questions for future studies of platelet genesis and megakaryocyte function in lung inflammation and other inflammatory conditions, bleeding and thrombotic disorders, and transplantation.”