In a groundbreaking discovery, researchers at UCSF have found that the lungs, not just the bone marrow, play a crucial role in producing red blood cells. This revelation could revolutionize how we approach stem cell transplants and blood-related diseases.
Traditionally, scientists believed that blood production only occurred in the bone marrow. However, the UCSF team found hematopoietic stem cells (HSCs) in human lungs that can produce red blood cells and megakaryocytes, which create platelets for blood clotting. This study, supported by the National Institutes of Health (NIH), suggests that lungs could become a significant source for life-saving stem cell transplants.
Mark Looney, MD, a UCSF professor, highlighted that lung HSCs might become another vital source of stem cells for treating diseases like leukemia alongside bone marrow.
In 2017, the UCSF team discovered that mice lungs produced 50% of their platelets and contained stem cells capable of generating all blood components. The researchers compared lung, bone marrow, and blood samples to confirm this in humans. They found lung HSCs, similar to bone marrow HSCs, were consistently present in the lungs and could produce red blood cells and megakaryocytes more efficiently than bone marrow HSCs.
Catharina Conrad, MD, PhD, noted that lung HSCs thrived in experiments and could restore bone marrow in HSC-deficient mice. This finding confirmed the cooperative role of lung and bone marrow HSCs in blood production.
Further analysis revealed that nearly 20% of stem cells collected during routine bone marrow transplants carried the signature of lung HSCs, indicating that these transplants include cells from both sources.
This discovery opens new therapeutic possibilities. With lungs serving as a backup reservoir for red blood cell and platelet production, this offers hope for improved treatments in hematopoietic stem cell transplantation.
Journal Reference:
- Catharina Conrad, Melia Magnen, Jessica Tsui, Harrison Jacob Wismer, Mohammad Naser, Urmila Venkataramani, Bushra Samad, Simon J Cleary, Longhui Qiu, Jennifer J Tian, Marco De Giovanni, Nicole Mende, Andrew D Leavitt, Emmanuelle Passegue, Elisa Laurenti, PhD, Alexis J Combes, Mark R. Looney. Decoding functional hematopoietic progenitor cells in the adult human lung. Blood. DOI: 10.1182/blood.2024027884
