Scientists suggest existence of central aging process
看片视频 biologist Siegfried Hekimi, whose research on the so-called "clock genes" in tiny worms caused a major stir several years ago, is the principal author of an analysis published in Science that suggests the existence of a central process of aging. The study, embargoed until 2 pm, February 26, 2003, is available on the web site.
Up until now it seemed that to increase human lifespan substantially, medicine had to find cures for every human disease, write the authors, Hekimi and MIT colleague Leonard Guarente. Instead, by analyzing the effects of mutations in yeast cells and in tiny worms, the two have discovered that tinkering with single-gene mutations can prolong the lifespan of worms, yeast and probably mice by as much as five times what might be expected in normal organisms. The key is the level of ROS (reactive oxygen species), which are toxic molecules that react with macromolecules and inhibit or destroy their functions. ROS are in fact a normal byproduct of metabolism, and to slow their effect on the aging process, doctors and nutritionists often recommend certain vegetables such as broccoli and spinach, which are rich in antioxidants. It remains controversial, however, whether this is effective. Many age-related diseases (e.g. Parkinson's, Alzheimer's, cancer, diabetes) involve oxygen stress damage by ROS. If the level of ROS is reduced, the lifespan is extended, according to Hekimi and Guarente's research.
These findings lead the biologists to believe that further research may produce novel genetic therapies for a wide range of age-related diseases. They conclude that the mechanisms of aging are more specific than previously thought, that death does not necessarily result from mostly independent degenerative processes and that if oxidative damage caused by ROS can be diminished, lifespan may be extended.
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