Biologists discover how yeast cells reverse aging

Jun 24, 2011 by Anne Trafton
A whole yeast (Saccharomyces cerevisiae) cell viewed by X-ray microscopy. Inside, the nucleus and a large vacuole (red) are visible. Image: NIH

Human cells have a finite lifespan: They can only divide a certain number of times before they die. However, that lifespan is reset when reproductive cells are formed, which is why the children of a 20-year-old man have the same life expectancy as those of an 80-year-old man.

How that resetting occurs in human is not known, but MIT have now found a gene that appears to control this process in yeast. Furthermore, by turning on that gene in aged yeast cells, they were able to double their usual lifespan.

If the human cell lifespan is controlled in a similar way, it could offer a new approach to rejuvenating or creating , says Angelika Amon, professor of biology and senior author of a paper describing the work in the June 24 issue of the journal Science.

“If we can identify which genes reverse aging, we can start engineering ways to express them in normal cells,” says Amon, who is also a member of the David H. Koch Institute for Integrative Cancer Research. Lead author of the paper is Koch Institute postdoc Elçin Ünal.

Rejuvenation

Scientists already knew that aged yeast cells look different from younger cells. (Yeast have a normal lifespan of about 30 cell divisions.) Those age-related changes include accumulation of extra pieces of DNA, clumping of cellular proteins and abnormal structures of the nucleolus (a cluster of proteins and nucleic acids found in the cell nucleus that produce all other proteins in the cell).

However, they weren’t sure which of these physical markers were actually important to the aging process. “Nobody really knows what aging is,” Amon says. “We know all these things happen, but we don’t know what will eventually kill a cell or make it sick.”

When reproduce, they undergo a special type of cell division called meiosis, which produces spores. The MIT team found that the signs of cellular aging disappear at the very end of meiosis. “There’s a true rejuvenation going on,” Amon says.

The researchers discovered that a gene called NDT80 is activated at the same time that the rejuvenation occurs. When they turned on this gene in aged cells that were not reproducing, the cells lived twice as long as normal.

“It took an old cell and made it young again,” Amon says.

In aged cells with activated NDT80, the nucleolar damage was the only age-related change that disappeared. That suggests that nucleolar changes are the primary force behind the aging process, Amon says.

The next challenge, says Daniel Gottschling, a member of the Fred Hutchinson Cancer Research Center in Seattle, will be to figure out the cellular mechanisms driving those changes. “Something is going on that we don’t know about,” says Gottschling, who was not involved in this research. “It opens up some new biology, in terms of how lifespan is being reset.”

The protein produced by the NDT80 gene is a transcription factor, meaning that it activates other genes. The MIT researchers are now looking for the targeted by NDT80, which likely carry out the rejuvenation process.

Amon and her colleagues are also planning to study NDT80’s effects in the worm C. elegans, and may also investigate the effects of the analogous gene in mice, p63. Humans also have the p63 gene, a close relative of the cancer-protective gene p53 found in the cells that make sperm and eggs.


This story is republished courtesy of MIT News (web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.

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nanotech_republika_pl
5 / 5 (1) Jun 24, 2011
A human homolog of NDT80 is C11orf9.
SteveL
5 / 5 (3) Jun 24, 2011
"I plan to live forever, of course, but barring that I'd settle for a couple thousand years. Even five hundred would be pretty nice." - Morganite saying (Sid Meier's Alpha Centauri)
Cave_Man
1 / 5 (8) Jun 24, 2011
Ever see or play dead space, if you start messing with cells to much we could all end up like the necromorphs, its like when cancer evolves to the point where it can reproduce fast enough.
nayTall
4.3 / 5 (7) Jun 24, 2011
if i'm of the last generation to die off, i'm gonna be really pissed.
emsquared
3 / 5 (4) Jun 24, 2011
I hope we have either figured out interstellar travel, and found another planet to colonize, or an infinite energy source by the time they figure this out...
zevkirsh
5 / 5 (2) Jun 24, 2011
i'd be willing to wager that a world where the rich could predictably purchase a health span of 120 or more years ( healthy until 120) would radically alter the history of mankind going forward.

think about the fact that the single largest destroyer of wealth is death. with an extra 40 years of healthspan the ultra wealthy would concentrate their power far more than ever previously imagine-able. This could be a good outcome for mankind if you believe that in doing so, the ultra wealthy would actually raise the overall standards of living for the whole world by encouraging cooperation or by encouraging productive competition (like the explosion in technology that followed from and as a result of both the first and second world war).....

but i think that that the lives of most people would suffer greatly. if not the lives of just about everyone but the ultra wealthy.

sort of a social/science fiction scenario.

Telekinetic
2.7 / 5 (7) Jun 25, 2011
"think about the fact that the single largest destroyer of wealth is death."
The single largest destroyer of a wealthy man is his widow.
Au-Pu
1 / 5 (3) Jun 25, 2011
Whilst this is very promising we need to do something about our population numbers and our breeding rate before we release something like this to our brain dead populations, otherwise as some have already said we had better have perfected space travel and have found habitable planets, otherwise we will populate ourselves into extinction.
gmurphy
2.7 / 5 (3) Jun 25, 2011
Imagine the benefit to humanity if Einstein or Feynman had their productive periods extended by 40 years?, unfortunately, it seems like the Bushes, Cheneys and Rumsfields of this world are most likely to be the benefactors of this research.
Telekinetic
2.6 / 5 (7) Jun 25, 2011
Imagine the benefit to humanity if Einstein or Feynman had their productive periods extended by 40 years?, unfortunately, it seems like the Bushes, Cheneys and Rumsfields of this world are most likely to be the benefactors of this research.

Actually, you will soon see the work of Vladimir Skulachev come to fruition, which is a very potent mitochondrial protectant called SkQ1, that will be available to all. As he puts it: "Not just for the stinking rich."
hard2grep
3 / 5 (4) Jun 25, 2011
As we get older, we realize the greater implications of life and death, thus realizing there is no point in living forever...
Moebius
1 / 5 (2) Jun 26, 2011
It's lucky that some cells evidently don't have this reproduction problem or we wouldn't be able to enjoy pizza.

(pizza and beer are reason enough to live forever and there are lots of other reasons too)
Telekinetic
2.1 / 5 (7) Jun 26, 2011
As we get older, we realize the greater implications of life and death, thus realizing there is no point in living forever...

Speak for yourself!
SteveL
5 / 5 (1) Jun 27, 2011
For the vast majoirty of us we scrimp, save and invest throughout the majority of our healthy work lives until we are nearly unable to be productive, (I'm talking about the majority of us, not those who can retire early) just to have enough to, so we hope, survive on the remainder of our days. It would be nice to only have to work for half of our healthy lives. However, if the extra 40 years or so is spent laying in a bed with someone else feeding me, turning me to prevent bed sores and whiping my arse - you can keep your extra 40 years.
Sinister1811
1 / 5 (5) Jun 27, 2011
Perhaps it would be possible to reverse aging (using this gene) in a process called gene therapy. Even if they only have some success, they could at least partially reverse the aging process. It would be interesting to find out what eventually becomes of these findings.