4 replies to this topic

[Ghostrider]

Theories of Biological Aging and Their Implications for Medicine

http://www.azinet.com/aging/

[eldar]

From the "Aging Theories" -summary:
"Some investigators report discovery of “aging genes” that apparently cause aging and do not appear to have any other function. Disabling these genes in nematode worm, mice, and other organisms has resulted in life span increases of as much as a factor of six."

Um, what?? By the factor of six? [huh]

[opales]

From the "Aging Theories" -summary:
"Some investigators report discovery of “aging genes” that apparently cause aging and do not appear to have any other function. Disabling these genes in nematode worm, mice, and other organisms has resulted in life span increases of as much as a factor of six."

Um, what?? By the factor of six?  [huh]

As in 6xnormal lifespan, not (10^6)xnormal lifespan.

The genes in question are SIR-genes (=silent information regulator), which appear to play a role in cell death. Paradoxically, upregulating the SIR genes (=probably enhancing cell apoptosis) also increases lifespan, and is purpotedly the mechanism through which for example resveratrol in red wine exerts its effects.

The SIR genes play a key role during mammalian development so they cannot be knocked out then. And even if knocked out during maturity, it would probably just lead to incontrollable cancer in mammals, problem not relevant to yeast.

The above statement is thus a bit misleading, as the six-fold increase in lifespan was observed in yeast, while other species have experienced much more modest increases (and as stated, via exactly opposite mechanism in cases of SIR-genes)

http://www.imminst.o...8540&hl=sir2&s=

[eldar]

As in 6xnormal lifespan, not (10^6)xnormal lifespan.

Yes, I didn't exactly think it would be 10^6, now that would be something [thumb]

The above statement is thus a bit misleading, as the six-fold increase in lifespan was observed in yeast, while other species have experienced much more modest increases (and as stated, via exactly opposite mechanism in cases of SIR-genes)

Ok thanks for the info. I suspected it might be something like this but the statament made it not so obvious.

[John Schloendorn]

This is correct, six-fold maximum life-span has been achieved in roundworms by a combination of interventions that are more modest on their own. The relevance of this model for human aging is controversial however.