Cellular Reprogramming Extends Telomeres In Mice

Reprogramming living tissue through the application of a specific combination of signals is able to induce strong telomerase activity

Shinya Yamanaka's team's creation of induced pluripotent stem cells revolutionised our understanding of cell biology. We learned that applying a specific protein 'code' was able to trigger dedifferentiation in cells - rendering them back to a more flexible state in which they can turn into another type of cell. This type of activity is normally blocked in adult cells, but reprogramming can restore embryonic like abilities. 

These factors have been refined to 4 Yamanaka factors (OCT4, SOX2, KLF4 and MYC). While these were previously only applied to cells in the laboratory, experiments have moved onto live animals in a bid to see whether exposure can reverse some aspects of the aging process. It showed extremely promising results when applied in a very short term manner; longer application forms teratomas, which are tumour like masses. 

In vivo reprogramming extends telomeres too

A Spanish team at the CNIO Telomeres and Telomerase Group led by Maria Blasco discovered that when genetically engineered mice expressed these Yamanaka factors for a time they found telomerase were extended during the process. These mice were provided with extra copies of the Yamanaka factor genes, that only turned on in the presence of a certain antibiotic. 

"What we have seen for the first time is the induction of telomerase 'in vivo'. To date, we do not know of any study that describes the induction of endogenous telomerase by defined transcription factors in the context of adult tissues"

While this reprogramming was also able to lead to teratoma growth in the longer term, under precise control it could prove to be a regenerative method in the future - winding back the clock just enough to reset some epigenetic changes and repair lost telomeres. 

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