Aging of stem-cells is reversible, as humans are heading towards a new dimension of stem cell therapy.
It was shown by a research team at Howards Hughes Medical Institute (HHMI), that an old mouse constantly exposed to blood from a younger mice enabled bone marrow stem cells to become young again.
The determining factor causing the rejuvenation of old stem cells into younger ones has not yet been identified. Yet, the result is in line with several other stem cell researches that are also portraying that aging of stem cells can be reversed.
This result is highly significant. It suggests the possibility to prolong the lifespan of stem cells. This would increase body’s resistance, and avoid age-related illness as well as degenerations.
One of the principal study investigators at HHMI, Amy J. Wagers, had found in earlier studies that blood of young mice has a maintenance capability to improve skin and muscle of older mice.
In this recent study, Wagers was scrutinizing whether hematopoietic (blood forming) stem cells present in the bone marrow could be replenished and renewed. Moreover, hematopoietic stem cells form all types of cells in our blood system. This includes red blood as well as immune cells.
According to Wagers, as stem cells become more prevalent as an animal age, their capacity to regenerate in the blood system is decreased. This makes the immune system less effective and more prone to disease and illnesses.
The experiment was conducted by combining the bloodstream of a pair of mice; one old mouse and one young. It was found after some weeks that the older mouse experienced a dramatic change in its hematopoietic stem cells.
The injection of blood from a younger animal into an older one, practically pushed the hematopoietic stem cells to a more active and young state. They became fewer in quantity yet the regenerative capacity of the blood cells turn out to be fully effective.
On the contrary, the same test was conducted on mice that had had its blood producing cells eradicated through radiation. A mixture of stem cells was transplanted into the older mice from a younger mouse. However, the rejuvenating effect of this pairing was ineffective. The stem cell was not turned to a younger state.
Source: Times of India
Thu, Feb 4, 2010
Stem cells