Note in Science page
Created Dec 01 10, Updated Dec 07 10 00:42
2 aging studies: telomeres and proteasomes go to comments

Telomere reactivation and partial reversal of aging in mice

Researchers at Harvard, manipulated telomerase activity in mice to study its effect on aging.


(green) telomeres at the tips of (blue) chromosomes [image taken from wired.com]

Telomerase less mice do age prematurely and are infertile with small brains, damaged intestines and poor senses of smell. Activating telomerase for a month (the used mutants have their telomerase gene “replaced” by an artificial construct expressing a telomerase protein fused to an estrogen receptor, that could only become active in the presence of a special form of estrogen) not only stopped premature aging, but rejuvenated the treated mice, with cells returning to a growth state, reversal of tissue degeneration, and increase in size of the spleen, testes, and brain.

Short lived mutant mice lacking telomerase activity do not age “normally” per se, but rejuvenation is anyhow a spectacular result. Data on (temporary) telomerase over-activation on mice with a normal telomerase activity is probably on its way… but will take more time!

article on harvard gazette
nature article

Proteasome and protein rejuvenation

French researchers from CNRS/ENS Lyon, instead of comparing old cells / organism versus young ones as everybody, decided to study aging from another perspective: looking at natural examples of rejuvenation: why / how / when germ cells become ‘young’ again!


Understanding aging by studying reproduction: the protein “damage” signal (white) drops sharply (white arrow) at a precise stage of the maturation of the oocytes destined to become embryos [image taken from physorg.com]

They monitored the cellular oxidation level during germ cell maturation (in C. elegans they developed a novel immunofluorescence technique to in situ visualize the level of protein carbonylation) and observed that:
1) the germline (of gametes) is damaged – precluding the idea that the germline does not age (the germline looks even more oxidized than the surrounding somatic tissues)!
2) at a precise stage of maturation of the oocytes the level of oxidation dropped suddenly!

Before reproduction, the proteins in our gametes are therefore “cleansed” and rejuvenated. Inhibition of the proteasome (which serves to degrade proteins) prevents this protein rejuvenation, hinting that correct protein degradation – via the proteasome – is an important process against cellular aging... (about protein degradation and aging, see also below: Stopping protein buildup and aging)

It would be nice if they could also visualize telomere lenght and/or telomerase activity in situ!

‘would be nice to be able to boost proteasome activity with drugs (e.g. oleuropein found in olive oil!) ... maybe acting on proteasome activator proteins and/or PARP-1

physorg.com article
Aging Cell article


Add a comment:

(required)

(will not be published) (required)

(optional)

(ascii characters only)