Scientists from the Institute of Medical Sciences of the University of Tokyo in Japan have discovered an unknown mechanism of blood aging, which prevents blood-forming cells from becoming young again. This is reported in an article published in the Journal of Experimental Medicine.
The researchers transplanted old hematopoietic stem cells (hematopoietic) cells from 20-month-old rodents into young 8-week-old mice. It turned out that this changes the activity of genes in old cells, which makes them look like young cells, but their functions are not restored. This is due to the fact that the pattern of DNA methylation (that is, the number of methyl groups attached to DNA) does not change. In other words, the cells are practically not rejuvenated.
At the same time, scientists hope that the results will help develop new treatments for age-related blood diseases. Further research will focus on identifying mechanisms that irreversibly affect the function of old hematopoietic stem cells.
Earlier, scientists at the University of California at Berkeley found out that the effect of rejuvenation is enough dilute the blood plasma with a mixture of saline and albumin, rather than adding the blood plasma of young mice. This demonstrated that the effect of rejuvenation and prolongation of life does not depend on young blood, but on the elimination of harmful factors in old blood.