What determines how long we live? It may all depend on how tough our stem cells are. A team at the University of Kentucky has found that the mouse strains that live the longest have stem cells in their bone marrow that are particularly good at repairing DNA.
The stem cells found in bone marrow and elsewhere are the source of new cells for many tissues in the body, from the liver to the immune system. The finding supports the theory that we age because our stem cells essentially run out of juice and can no longer cope with the degree of cell turnover needed to keep our organs young.
If so, it might be possible to extend life by altering or replacing our stem cells to make them better at withstanding DNA damage, an idea a growing number of researchers are looking at.
The team tested bone marrow stem cells from various mice strains to see how good they were at resisting DNA damage. By breeding the mice, they were able to home in on the regions in the mouse genome associated with this trait.
In what they refer to as a "striking overlap", it turned out that several of those regions had previously been linked to longevity.
Now the researchers think they have found a gene in one of those regions, located in chromosome 11, that could explain the overlap. Scientists think the same correlation between longevity and stem cell hardiness will be found in all mammals.
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