Biologists discover how yeast cells reverse aging

From PhysOrg:

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.

…When yeast cells 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 genes targeted by NDT80, which likely carry out the rejuvenation process.

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