Posted on 12/04/2005 12:37:45 PM PST by narses
It's been well established with previous research that an extra copy of the SIR2 gene can promote longevity in yeast, worms and fruit flies. But a counterintuitive experiment that deleted the gene entirely has resulted in one of the longest recorded life-span extensions in any organism. The new study, by scientists at the University of Southern California, suggests that SIR2 promotes, rather than retards, aging. The findings may throw a spanner into the works of biotech companies and their anti-aging drug development programs.
Author of the study, Valter Longo, said deleting the gene altogether in yeast resulted in a dramatically extended life span - up to six times longer than normal - when combined with caloric restriction and/or a mutation in one or two genes, RAS2 and SCH9, that control the storage of nutrients and resistance to cell damage. Longo added that human cells with reduced SIR2 activity also appeared to confirm that SIR2 has a pro-aging effect, but these results were not included in the Cell paper.
Longo believes that SIR2 (and possibly its counterpart in mammals, SIRT1) may stop an organism from entering an extreme survival mode characterized by the absence of reproduction, improved DNA repair and increased protection against cell damage. Organisms usually enter this mode in response to starvation. According to Longo, the SIR2 deletion made the yeast extraordinarily resilient under stress. "We hit them with oxidants, we hit them with heat. They are highly resistant to everything. What they're doing is basically saying, 'I cannot afford to age. I still have to generate offspring, but I don't have enough food to do it now', he remarked."
While any kind of anti-aging treatment for humans is still a long way off, Longo is excited about the possible implications for another area of research. "Cells may be able to speed up their DNA repair efforts. All organisms have the ability to repair harmful mutations in their DNA, whether caused by age, radiation, diet or other environmental factors," said Longo. And while many researchers believe DNA repair systems are already running flat out, the organisms in Longo's experiment suggest otherwise.
Longo's group began studying SIR2 in 2000, just after a well-known set of experiments by Leonard Guarente at MIT showed that over-expression of the SIR2 gene could extend life span beyond its natural limit. But Longo went in the opposite direction. "We were convinced that SIR2 had the potential to be a more potent pro-aging than an anti-aging gene. And the reason was in part because of the similarity with this other gene, called HST1, which negatively regulated so-called protective genes. So we set out to test whether SIR2 could do the opposite of what everybody said it does," he explained. Longo doesn't question Guarente's finding of a moderate increase in life span when SIR2 is over-expressed, but he believes his work shows that much greater potential gains may lie in the opposite direction.
Source: University of Southern California
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But how about when not combined?
Though I can believe folks who eat less would tend to live longer. Less scale to clog up the pipes.
I always had a sneaking suspicion that immortality -> no sex drive. I mean, living forever obviates the need to reproduce, right? Sex only feels good because we wouldn't do it otherwise, and it's kind of necessary that we do it.
Ping
pingworthy?
The sociology of greatly increased life spans is fascinating to contemplate.
'I cannot afford to age. I still have to generate offspring, but I don't have enough food to do it now',
Nothing worse than making whoopie when you're hungry and have food on the mind.
Interesting - the boomers have always been on a self-improvement path - cosmetic surgery, invitro - a host of other selfish goals.
Aging is part of life - it is an assessment time where we can finally "get it" and it should be embraced as such in order to put down for history our findings. Not to run from the natural process, but try to stay as healthy as we can so our minds can impart the wisdom to those who will listen.
Do not get me wrong - I am all for improved life - but ad infinitum? No way. I am not certain I want to see that far ahead because I think we have made a bit of a mess of this planet and hope some who follow will concentrate on finding solutions to the problems we have created. Not just selfish goals like immortality.
One other concern - overpopulation. It is almost mandated that some of us die so make room for the young. Even if the young are less than plentiful - do not forget those civilizations and societies who are making huge numbers of their own.
This supports that idea.
When mankind can live to 200 years wars will be way less prevalent.
Slavery abolished sans Civil War?
The sociology of greatly increased life spans is fascinating to contemplate.
It becomes seriously difficult to rewrite history. Would the founding fathers have not stopped FDR? Prohibition? WOsomeD? "the right of the people to keep and bear Arms, shall not be infringed."? Income tax?
One sort of has to go forward with their speculations.
I think we've had a thread on this. I'm looking for it ...
It is in the Bible :)
Gen:5:20: And all the days of Jared were nine hundred sixty and two years: and he died.
Gen:5:21: And Enoch lived sixty and five years, and begat Methuselah:
Gen:5:22: And Enoch walked with God after he begat Methuselah three hundred years, and begat sons and daughters:
Gen:5:23: And all the days of Enoch were three hundred sixty and five years:
Gen:5:25: And Methuselah lived an hundred eighty and seven years, and begat Lamech:
Gen:5:26: And Methuselah lived after he begat Lamech seven hundred eighty and two years, and begat sons and daughters:
Gen:5:27: And all the days of Methuselah were nine hundred sixty and nine years: and he died.
Gen:5:28: And Lamech lived an hundred eighty and two years, and begat a son:
Gen:5:30: And Lamech lived after he begat Noah five hundred ninety and five years, and begat sons and daughters:
Gen:5:31: And all the days of Lamech were seven hundred seventy and seven years: and he died.
Gen:5:32: And Noah was five hundred years old: and Noah begat Shem, Ham, and Japheth.
Gen:6:3: And the LORD said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.
Gen:7:6: And Noah was six hundred years old when the flood of waters was upon the earth.
Gen:9:28: And Noah lived after the flood three hundred and fifty years.
Gen:9:29: And all the days of Noah were nine hundred and fifty years: and he died.
Nah, they'd just raise the retirement age.
Aging is part of life.
Um, aging -- degenerative -- leads to death. As such it is part of death.
Not to run from the natural process, but try to stay as healthy as we can so our minds can impart the wisdom to those who will listen.
Staying as healthy as possible leads to youth-rejuvenating/non-aging immortality. History is replete with man increasingly understanding nature to control nature. And has greatly benefited from his ability to do what nature sans consciousness cannot do alone.
I am all for improved life - but ad infinitum? No way. I am not certain I want to see that far ahead
"No way".... "not certain"? Seems you haven't given serious thought to the subject. Are you certain you want to die? And when would be a good time?
Not just selfish goals like immortality.
Man, aside from the Dark Ages, has greatly improved himself, family and society. Men perusing science and business have not set out to harm or kill his fellow man. That cannot be said of leaders perusing religion and politics.
One other concern - overpopulation. It is almost mandated that some of us die so make room for the young.
Yeah, there's limited space in our solar system. [/sarcasm] Man's conscious mind is a problem soloing entity. Evidence history.
You may have to go forward with your speculations. I do not. I have no
such boundry limiting my thought process.
I don't think so. People who start wars don't fight in them.
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