I heard somewhere that telomere elongation can only occur during replication stage. Not sure if true and if this affects telomerase activation.
Yes, that's true, cells have to be in s-phase for the telomere to be accessible (*).
But like so many things in biology it may not be an absolute rule. And this is where short telomeres being more easy to elongate come in, because the end is more accessible.
The telomere end is completely accessible during DNA-replication, as it has been unrolled. And it is completely inaccessible when folded up and tucked in. But in-between these two states there are situations where the telomere end has some accessibility, and this is enhanced with a short telomere because it is more difficult to tuck it in.
This is the proposed mechanism behind rejuvenation of old people using telomerase activators that are not strong enough to lengthen telomeres back to youthful length, but may be strong enough to take you back some of the way, or rather maintain an equilibrium point at some greater length than would otherwise be the case, with greater mortality than is optimal, but lower than it would otherwise have been.
It is virtually impossible to say how many years this might give you, or how much extra health span. But Bill Andrews is 73 and an endurance runner. He doesn't look young. And doesn't look to be getting any younger. But the does look much better than most his age.
(*) It may be a mechanism for inhibiting telomerase activation as well, i.e. short telomeres have one telomerase blocking mechanism removed, but this is not confirmed.
Edited by QuestforLife, Yesterday, 02:40 PM.
LongeCity
