Nobel Prize, Telomeres, Astragalus And Longevity
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The Nobel Prize in Physiology or Medicine 2009 was awarded jointly to Elizabeth H. Blackburn, Carol W. Greider and Jack W. Szostak "for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase"
Telomeres delay ageing of the cell
Scientists now began to investigate what roles the telomere might play in the cell. Szostak’s group identified yeast cells with mutations that led to a gradual shortening of the telomeres. Such cells grew poorly and eventually stopped dividing. Blackburn and her co-workers made mutations in the RNA of the telomerase and observed similar effects in Tetrahymena. In both cases, this led to premature cellular ageing – senescence. In contrast, functional telomeres instead prevent chromosomal damage and delay cellular senescence. Later on, Greider’s group showed that the senescence of human cells is also delayed by telomerase. Research in this area has been intense and it is now known that the DNA sequence in the telomere attracts proteins that form a protective cap around the fragile ends of the DNA strands.
An important piece in the puzzle – human ageing, cancer, and stem cells
These discoveries had a major impact within the scientific community. Many scientists speculated that telomere shortening could be the reason for ageing, not only in the individual cells but also in the organism as a whole. But the ageing process has turned out to be complex and it is now thought to depend on several different factors, the telomere being one of them. Research in this area remains intense.
Most normal cells do not divide frequently, therefore their chromosomes are not at risk of shortening and they do not require high telomerase activity. In contrast, cancer cells have the ability to divide infinitely and yet preserve their telomeres. How do they escape cellular senescence? One explanation became apparent with the finding that cancer cells often have increased telomerase activity. It was therefore proposed that cancer might be treated by eradicating telomerase. Several studies are underway in this area, including clinical trials evaluating vaccines directed against cells with elevated telomerase activity.
In conclusion, the discoveries by Blackburn, Greider and Szostak have added a new dimension to our understanding of the cell, shed light on disease mechanisms, and stimulated the development of potential new therapies.
nobelprize.org
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Anti-Aging Pill Targets Telomeres at the Ends of Chromosomes
scientificamerican.com
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A link between telomere shortening and oxidative stress was found in aging people and patients with cancer or inflammatory diseases. Extracts of Astragalus spp. are known to stimulate telomerase activity, thereby compensating telomere shortening.
ncbi.nlm.nih.gov.
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Astragalus the power house immune building plant
rejuvenated.com.
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10 Proven Benefits of Astragalus Root (#4 Is Vital)
draxe.com |
