For more than a century, anatomy textbooks upheld an unquestioned dogma: bone marrow is the sole nerve center responsible for producing our blood cells. However, research from the University of California, San Francisco (UCSF) published in the journal Nature radically transformed this principle by demonstrating that the lungs play a massive role in hematopoiesis.
Using advanced intravital microscopy, researchers tracked cellular behavior in real time and discovered that a colossal population of megakaryocytes—the giant cells responsible for fragmenting to create platelets—resides and actively works within the pulmonary microvascular bed. In fact, the lungs generate more than 50% of the body's total platelets, releasing millions of these units essential for clotting and wound healing directly into the bloodstream.
The most fascinating finding was confirming that the lungs also house their own reserve of blood stem cells. When scientists observed models with damaged or compromised bone marrow, these pulmonary progenitor cells migrated to the bones to replenish them and rebuild blood production, acting as a biological emergency station.
This discovery not only rewrites basic physiology, but also opens promising avenues for understanding disorders such as thrombocytopenia, lung transplant rejection, and various inflammatory diseases that directly link respiration to vascular health.
Source: Nature (2017) / University of California, San Francisco (UCSF)
