The quest for longer and healthier life, if not immortality, has been part of the human experience since we evolved the ability to recognize the total annihilation of individual death. Our understanding of the biology of aging at the molecular level is advancing so rapidly that it appears inevitable that another decade or two of life will be enabled before long. A new step in what may be the right direction has just been published by researchers at the University of California, Berkeley.
The ravages of aging appear to be related to oxidative stress combined with telomere exhaustion, along with many other known and unknown factors. The subject of the new Berkeley study is a class of proteins called sirtuins that are known to play a central role in regulating aging and longevity in many non-human models (such as mice).
There is good evidence that these proteins also play a similar role in humans. For example, research has shown that, of two variants of the SIRT3 sirtuin protein (known to have strong anti-oxidant properties), humans who live past 90 years of age only have one of the variants in their bodies, the variant that enhances production of SIRT3. The difference between the two variants results from a change of one gene by one mutation, and appears to be sufficient to significantly affect an organism’s longevity. This suggests a strong link between SIRT3 and longevity.
The genetics of longevity are quite interesting, but still more interesting would be finding an approach to offset the hand you were dealt at birth, or better yet, to stack the deck. The authors of the Berkeley study decided to see if SIRT3 could rejuvenate blood stem cells extracted from old mice.
Their first step was to see what happened as mice, which did not possess the SIRT3 gene, aged. When young, these "knockout" mice followed the same course of aging as did a set of normal control mice. However, when the mice were two years old (about an average lifespan for a lab mouse), the knockout mice had far fewer blood stem cells than did the control group.