Israeli scientists offer insight into aging

JERUSALEM - Israeli researchers find clues into what and how humans age, which opens path on how to reverse the aging process.

The study, led by Haifa University researcher Hila Toledano and published in the journal Nature, helps explain why adult stem cells age and offers hope of reversing the process.

Hilla Toledano's research, conducted at the Salk Institute in California, found that the let-7 molecule in adult stem cells causes damages in another molecule known as Upd, which sends signals to other cells.

This disruption of signals between the cells that compose adult stem cells may be the cause of the aging process, Toledano's research found.

"The discovery may offer a promising route to fight the ageing process in stem cells and allow the elderly body to maintain tissues and heal injuries as adult people do," Toledano told Ha' aretz daily.

As humans age, the let-7 molecule stops producing a protein known as Imp, which stabilizes the Upd molecule. Without the protein to balance it, Upd then becomes unstable and cannon send signals to other cells in the stem cell, and then the stem cells stops dividing, which leads to aging.

"We basically mapped the domino effect of the let-7 molecule," she said. "There are a few studies of muscle stem cells that point to the molecular mechanisms of the aging-related decline of stem cell function. What's novel to our work is the finding that this aging-related decline comes from the niche (other cells) rather than the stem cells themselves."

Now the challenge is to reverse the aging effect by supplying Upd molecules with the Imp protein to maintain them stable, which according to Toledano, has worked with fruit flies.