I wouldn't go as far as to call it a master switch. Telomeres can affect the expression of a few genes that are located near the end of the chromosome. That mouse experiment showed that artificially shortened telomeres can create a phenotype that looks very much like normal aging, but that can be reversed by telomere extension. That doesn't mean that lengthening telomeres will do the same thing to a human with normal aging. Even if all telomeres were reset to a child-like length, you'd still have crosslinks, lipofuscin, amyloids, etc.
Ok, then look at the 3 types of human cells that were given the gene change to have them creating telomerase by these guys
http://www4.utsouthw...w_research.htmlExtension of life-span by introduction of telomerase into normal human cells
Science 279: 349-353 (1998)http://www.the-scien...ng-Human-Cells/Those came originally from about a 86 year old man..Hayflick, and normally would have divided a few more times and stopped. In the 2000 article it said they had gone past 400 doublings, and going and going and going. These cells not only did this, but they also did not age anymore. Not only this but they got younger in appearance and function. They were almost identical to brand new cells, almost. Just as the lab rats that almost grew back all the brain lost to advanced aging, or liver or.............
When we talk about all the diseases and conditions, such as glycation we are talking about the world of damaged cells that are failing to operate properly. I am saying this will disappear in a world of properly functioning young cells.
Lets take a look at a more recent Harvard mice story that has little to do with telomerase or telomeres. In it they gave a single protein to old mice
GDF-11. It is normally in young mice in larger amounts and becomes less and less as they grow older, and when added back into old mice their hearts with thickened heart walls like old humans the hearts were reduced in size and thickness, resembling the healthy hearts of younger mice in 30 days. Hey, that's like the same time period telomerase was reactivated the old knockout mice and made them young.
http://news.harvard....hearts-younger/OK where am I going with this?? If the cells become young from the re lengthened telomeres, then I will bet funny little things like the increase of things, such as GDF-11 will happen a lot again ordering up repair after repair. Crosslinked proteins interfering with their function, but we can't have that, so whammo repair kicks in and new non crosslinked and fully functioning proteins take their place.
Remember too telomerase is more than a telomere builder but also a DNA fixer though it can't fix it all. Here is another little recently discovered tidbit. Cancer carefully monitors and controls its telomere length and it doesn't just mean to make sure they don't get to short and die, but also so they don't get too long. Because, if they get longer the cancerous gene coding switches back to normal, just like before the coding changes from short telomeres.
Edited by free10, 09 August 2013 - 04:46 AM.