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takyon [soylentnews.org] writes:

Scientists at ETH Zurich identified 30 genes [www.ethz.ch] in the nematode C. elegans, zebrafish, and mice that have an effect on aging and lifespan:

After combing through 40,000 genes from three different organisms, scientists have identified 30 that have a big effect on aging and lifespan. Influence only one of the 30 genes and the animals stay healthier and live longer.

[...] By conducting experiments in which the mRNA of the corresponding genes were selectively blocked, the researchers pinpointed their effect on the aging process in nematodes. With a dozen of these genes, blocking them extended lifespan.

One of these genes proved to be particularly influential: the bcat-1 gene. "When we blocked the effect of this gene, it significantly extended the mean lifespan of the nematode by up to 25 percent," says Ristow.

The researchers were also able to explain how this gene works: The bcat-1 gene carries the code for the enzyme of the same name, which degrades branched-chain amino acids. Naturally occurring in food protein building blocks, these include the amino acids L-leucine, L-isoleucine, and L-valine.

When the researchers inhibited the gene activity of bcat-1, the branched-chain amino acids accumulated in the tissue, triggering a molecular signaling cascade that increased longevity in the nematodes—and extended the amount of time the worm stayed healthy.

As a measure of vitality, the researchers measured the accumulation of aging pigments, the speed at which the creatures moved, and how often the nematodes successfully reproduced. All of these parameters improved when the scientists inhibited the activity of the bcat-1 gene.

The scientists also achieved a life-extending effect when they mixed the three branched-chain amino acids into the nematodes' food. However, the effect was generally less pronounced because the bcat-1 gene was still active, which meant that the amino acids continued to be degraded and their life-extending effects could not develop as effectively.

Branched-chain amino acid catabolism is a conserved regulator of physiological ageing [nature.com]

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