
Why Do Cells Age? Extremely Long-Lived Proteins - llambda
http://www.sciencedaily.com/releases/2012/02/120203180905.htm
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reasonattlm
This is most likely a lesser contribution - and remember this is only of
practical interest in very long-lived cells, such as the neurons that never
turn over and are as old as you are. Compare this mechanism with failure of
the lysosome due to buildup of indigestible lipofuscin, or mitochondrial DNA
damage, or the cell being battered by higher levels of surrounding AGEs and
amyloid or other aggregates, and so forth.

What this does tend to point out, however, is the very long term need for ways
to replace or completely repair currently irreplacable cells. That isn't the
low-hanging fruit, but it's the sort if thing to be working in once SENS is
realized.

By then, of course, the options will be veering off into the space of
molecular manufacturing and medical nanorobotics and synthetic replacements
for biological molecular machinery.

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polyfractal
As a biologist, this is a major pet-peeve of mine: we don't need "medical
nanorobotics". Not only is this a nonsense term, but nature has already
provided a much better solution.

It's called an enzyme.

Enzymes are hugely efficient "nanorobots" that don't require science fiction.
They "manufacture molecules" all the time, every day, at catalytic rates that
would make high-tech manufacturing factories blush.

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reasonattlm
"Need" is a slippery word, and while it is indeed likely that many or most
nanoscale tools of future medicine will be fairly directly derived from cells
and cell components, and we could probably achieve all of the design goals for
agelessness and disease immunity with those, "medical nanorobotics" is not a
nonsense term. It explicitly refers to the design and construction of non-
biological nanoscale-featured devices - which is a concept far removed from
enzymes. There are some things you can do with these designs that are
impossible for presently available or plausible biological machinery.

See, for example:

<http://en.wikipedia.org/wiki/Respirocyte>

<http://jetpress.org/v16/freitas.pdf>

<http://www.nanomedicine.com/>

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polyfractal
Everything you linked is still theoretical/hypothetical.

Those links basically prove my point. What you linked is possible _right now_
using biology. We don't need nanorobots to modify DNA, we have enzymes and
viruses that work really, really well.

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z0ot
This reminds me of a paper I read a few days ago. Melatonin, when bonded to
MT1 receptors, can prevent cell death from neurodegenerative such as
Huntingtons and Alzheimer's. The melatonin prevents the mitochondria from
releasing an enzyme which lights the fuse on cell death mechanisms. Very, very
cool.

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brador
Link to paper please...

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carbocation
Probably <http://www.ncbi.nlm.nih.gov/pubmed/21994366>

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mkramlich
Want to create a startup that truly has an impact on the world? Make the
breakthroughs needed to deliver immortality.

~~~
pyre
The problem is that there is no immediate solution. You could bang away at the
problem for the better part of a decade and still be 'almost there.'

~~~
pjscott
You'll be doing fine if you manage to extend people's lives by at least one
year per year. Think of it as lowering your burn rate. :-)

Of course, that's easier said than done, but living longer, healthier lives is
important.

~~~
pyre
Solving the 'immortality problem' isn't like grinding in an RPG. You don't
slowly increase the maximum lifespan at regular intervals.

Immortality would probably involve solving various different, discrete
problems. When I said 'almost there' I meant in solving one of these issues.

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nazar
Cells age _mostly_ because of telomere shortening.

<http://en.wikipedia.org/wiki/Telomere#Telomere_shortening>

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polyfractal
Sorta, but I wouldn't classify it as "aging". It's more akin to automated
self-destruction after a certain amount of time. Aging implies a slow
breakdown of function, whereas the limit imposed by telomeres is more of a
binary event.

You're good until you run out of telemoeres, then shit gets crazy and you
enter apoptosis because your cell is no longer functioning correctly.

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nazar
Yes, thank you for correction, I used the wrong word. What I tried to say is
that telomere shortening is the main cause of cell destruction, and unless its
solved, cell death is inevitable

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polyfractal
Sorry to correct you again (I'm a biologist...I can't help it!), but cell
death is actually a very good thing. Your cells are programmed to die so they
don't turn into cancer, or start degenerating into something equally
unpleasant.

Aging occurs because your body becomes less capable of replacing these cells
over time, and either replaces with less robust cells or stops entirely. Or
you get cancer.

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nazar
Hey, I always welcome constructive corrections. Btw, I actually attended
International Biology Olympiads twice, but it was too long ago for me to
remember the details.(Ever since I was too remote from biology)

~~~
polyfractal
Awesome! I hope it was a good experience! More people should be exposed to
biology, it is very cool and under-appreciated. :)

