Researchers at UC San Francisco have made a notable discovery, identifying blood stem cells in the lungs for the first time. This finding challenges the long-held belief that hematopoietic stem cells (HSCs), which are responsible for producing various blood cell types, are predominantly located in bone marrow.
Traditionally, bone marrow has been recognized as the primary site for blood cell production, making bone marrow transplants a critical component in the treatment of blood-related diseases, including cancers like leukemia. The new study, published in the journal Blood, suggests that the lungs may also serve as a significant reservoir for these vital stem cells.
Mark Looney, the senior author of the study and a professor at UCSF, articulated the potential implications of this discovery. He noted that lung-derived HSCs could provide an alternative source for transplants, addressing the ongoing need for donors, particularly from diverse racial and ethnic backgrounds. The research, which began in 2017, initially found HSCs in mouse lungs capable of generating red blood cells and white blood cells. Subsequent analyses of human lung tissue confirmed the presence of similar stem cells.
The team successfully extracted these cells and cultivated them in laboratory settings, demonstrating their ability to produce various blood cell types, including megakaryocytes responsible for platelet production. When introduced into immunocompromised mice lacking their own HSCs, the human HSCs effectively generated blood cells.
While the exact purpose of these lung HSCs remains unclear, researchers speculate that they may act as a backup system for blood cell production in response to the body’s needs, particularly in critical situations requiring increased blood components. This research opens new avenues for understanding blood cell production and potential therapeutic applications.