[extropy-chat] AGING: real progress

[Robert J. Bradbury]

Well, we finally have some real progress on understanding aging.

It looks like SIRT1 (homologue of yeast Sir2), regulates FOXO3
which in turn regulates the enzymes that resist oxidative stress.

Science Daily:
http://www.sciencedaily.com/releases/2004/02/040220081158.htm
PubMed Abstract:
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14976264&dopt=Abstract

Now *before* everyone gets all excited please note that the
gene regulation goes against apoptosis (programmed cell death)
and for stress resistance (particularly from free radicals).
That is probably a reasonable strategy in short lived animals
(which include most that scientists work on in labs).

However in long lived larger organisms one does not want to suppress
apoptosis (because it will probably lead to an increase in cancer).
In long lived species one needs to allow apoptosis or improve the
ability of the immune system to recognize and eliminate cancer cells
(which people are working on).  One also needs to promote stem cell
replacement of lost cells (which we have some of but it probably isn't
as finely tuned as one would like).

But it is clear that this provides a key piece of the puzzle as
to how cells manage the repair/replicate/die decision processes.
Now whether the actions of FOXO3 on apoptosis and stress resistance
have been split in longer lived organisms (so one has 2 genetic
programs under individual controls rather than just a combined
genetic program with only 1 control factor) remains to be seen.

Robert