Red blood cell production in the lungs, new functions of the cerebellum, and trying to reverse aging in mice
A new study finds that most of our blood cells are made in the lungs, not bone marrow. Using genetically modified mice that expressed a green fluorescent protein (GFP) and photon microscopy, scientists were able to track blood platelets as they circulated around the body in real time. Surprisingly, they found a large population of megakaryocytes, responsible for the production of blood cells, in the lungs. This population of megakaryocytes was found to produce upwards of 10 million platelets per hour at least half of the body’s total platelet production. Further experiments, found another population of megakaryocytes just outside the lung tissue which is about 1 million per lung. Additionally, using mice with no stem cells in the bone marrow (eliminating blood cell production there), they found that cells from the lungs migrated to and facilitated blood cell production in the bone marrow. Because of technological advances in genetic engineering and microscopy, this study challenged a decades-old assumption, central to the field of biology and medicine. This study will of course need to be replicated and assessment performed of whether these findings generalize to humans.