Telomeric Theory of Aging

Austin Seo (Hae Jin) haejin at netinfo.ubc.ca
Tue Aug 18 16:20:00 EST 1998


Actually much of this work has been done already. And although no one has
done it in a whole animal (i.e. mouse), they have introduced telomerase into
cells of the basal epithelia...and they continue to divide quite happily (>80
vs the usual 40 rounds of cell division).

In vitro it is clear that telomere length and its subsequent truncation is
correlated to the death of a cell. As telomere length shortens, there is a
critical point where a cell is fated to die, or something happens which
causes cells to immortalize or die...those that immortalize are found to have
an upregulation of telomerase activity (but it is not clear that they are
directly related).  But it is not clear what telomere length really is
important for nor what the rate of telomere truncation is. A case in point is
the lack of difference in the life span between M. musculus (who have huge
telomeres...150 kb?... and little or no telomerase activity) versus M.
spretus (who have shorter telomeres...80kb? and more detectable telomerase
activity).

The role of telomerase and telomeres in aging hasn't been clearly established
yet. Telomerase activity is found to be higher in progenitor cells of the
epithelia, immune system, but not in more differentiated cell types (quite
unlike what the original poster presented wrto the immune system) and is
generally higher during embryogenesis.

Remember that all the experiments done to date were performed in very clean
almost sterile environments. There are many other factors that are involved
in aging which supercede the importance of telomerase/telomeres.

James wrote:

> > It seems that this would be an awsome experiment if it could be
> > performed. It could help us deterimine just how much telomerase
> > therapy could increase lifespan, whether activiation of telomerase
> > causes cancer, and whether there are any other side effects.
> >
> > Best Regards,
> > William
> >
>
> My guess is that it is currently in the works.  Anyone have any real info?


--

Austin Seo (Hae Jin)

Graduate Programme in Neuroscience
Centre for Molecular Medicine and Therapeutics
e-mail: haejin at netinfo.ubc.ca





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