[extropy-chat] AGING: real progress
jpnitya at sapo.pt
Mon Feb 23 07:30:33 UTC 2004
Although the p66 mice live longer, there is little information regarding
specific age-related pathologies. I don't remember reading anything
regarding cancer rates in p66 -/- mice, so I would assume cancer rates do
not change but I could be wrong.
As for WS and p66, I think you missed my point. At a molecular level they
may have different roles. Yet I was looking at aging from a cell population
perspective. At a tissue level, p66 decreases apoptosis, meaning tissues
can have cells dividing slower or have less cells dividing to maintain
tissue homeostasis. In WS, cells divide slower and less vigorously, meaning
there must be more cells dividing to maintain homeostasis. The bottom line
is: in p66 you have a higher production of cells while in WS you have a
lower production of cells, meaning p66 allows cells to divide less
frequently while WS obliges cells to divide more frequently. From this
perspective it makes sense that p66 delays aging while WS decreases
longevity and accelerates aging.
Just like you can't understand a painting by looking too closely, maybe you
have to zoom out from the molecular perspective to understand aging.
Apoptosis is also affected by WS, though I'm not sure whether it's
increased or decreased.
A couple of references on p66:
Migliaccio, E., Giorgio, M., Mele, S., Pelicci, G., Reboldi, P., Pandolfi,
P. P., Lanfrancone, L., and Pelicci, P. G. (1999). "The p66shc adaptor
protein controls oxidative stress response and life span in mammals."
Nemoto, S., and Finkel, T. (2002). "Redox regulation of forkhead proteins
through a p66shc-dependent signaling pathway." Science 295(5564):2450-2452.
And a couple of references on the link between WS and apoptosis:
All the best,
PS: A good question then would be why mice mutant for WRN do not age faster
since their cells divide slower in culture.
Joao Magalhaes (joao.magalhaes at fundp.ac.be)
Website on Aging: http://www.senescence.info
Reason's Triumph: http://www.jpreason.com
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