Re: Human Cell Lifespan Extended

From: Joao Pedro (jpnitya@mail.esoterica.pt)
Date: Fri Jan 16 1998 - 02:53:31 MST


Hi!

CurtAdams wrote, amongst other ideas from him and others:
> One general approach would be to take out crypt cells (cells from tissue that
> divide to replace those that die), proof them for pre-cancerous mutation,
> telomere-lengthen the "clean" ones, and then put them back without telomerase.

Here's a thought, our somatic cells have the genes to produce
telomerase. All we have to do is "order" them to express these genes.
Since these genes are expressed during the early stages of development
and germ cells, if we could find out external impulses to control their
expression, we could have immortal cells without the need for some
dangerous and expensive procedures. Inserting genes, filling the body
with telomerase, removing cells and treat them for later implantation,
it all seems very hard and expensive. Also, changing the genes is
something very difficult. Only a few cells treated by gene therapy do
survive, only a few mice -- less than 20%, if I remember correctly --
treated by genetic engineering do born healthy!

John K Clark wrote:
> True. Perhaps neurons age because the support they receive from other cells
> that do divide degrades, or perhaps telomere shorting is not the only clock
> in every cell, but if one clock can be found so can another.

Could be that neurons fail because the glial cells also fail. But its
still a big problem to prevent aging in the brain -- probably the
biggest of them all. Not only do we have to make the glial cells
immortal -- which is apparently difficult and dangerous because any
mistake leads to death or brain damage --, but we might also have to
change the neurons -- something even harder and incorporating huge
risks.

One last thing, telomerase could indeed have more functions than just
correct the telomers. I read a study (if you want to, I'll look for it)
a few months ago that showed that telomerase is highly active in cancer
cells with their telomers "fully-extended" -- not the exact definition,
but you get the point. Also, telomerase is active in leukocytes, but I
haven't found the extension of that action.

See ya,

-- 
         Hasta la vista...
"Life's too short to cry, long enough to try." - Kai Hansen
Reason's Triumph at: http://homepage.esoterica.pt/~jpnitya/


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