British researchers have identified a process leading to a “disastrous” change in blood composition in old age, increasing the risk of cancer and reducing the ability of white blood cells to fight infection.
Accelerated growth of “selfish” stem cells
Yes the aging is a complex process, it has long been suspected that the gradual accumulation of mutations in cells gradually degrades the body’s ability to function properly. Published in the journal Naturethis new research led by scientists from thecambridge university suggest that this reasoning is flawed, or at best incomplete.
Peter Campbell and his colleagues studied the blood cells of people of all ages, from newborns to septuagenarians and octogenarians. It turned out that adults under 65 had a wide range of red and white blood cells produced by a diverse population of 20,000 to 200,000 different types of stem cells in their bone marrow. In older subjects, the picture was radically different. About half of their blood cells came from just 10 or 20 separate stem cells.
While most mutations that blood stem cells undergo are harmless, with age some of them can accelerate stem cell growth. selfish ”, which become the majority and lead to the production of blood cells of lower quality. Linked to blood cancers and anemia, these also make us less resistant to infections.
Scientists believe similar changes occur in all organs of the body, from skin to brain, which could explain why we typically experience healthy aging for decades before a more rapid decline in our 70s or 80s.
Important implications
According Elisa Laurentico-author of the study, chronic inflammation, smoking, infection and chemotherapy could potentially promote the decline in blood stem cell diversity associated with aging.
« It is possible that certain factors can also slow down this process. We now have the exciting task of understanding how these newly discovered mutations affect blood function in older adults, so we can learn how to minimize disease risk and promote healthy aging.. »
« Our work suggests that a common set of processes are at work », Adds Campbell. « Ultimately, the goal would be to slow down or intervene in the aging process, but we see at least one possibility of using this method to measure biological age.. »