Scientists from Salk Institute from San Diego, California have successfully reversed the ageing process in middle-aged and elderly mice using a novel cellular rejuvenation technique.
Making use of four molecules (also known as the Yamanaka transcription factors), researchers have shown that they can partially reset the mic cells to a more youthful state.
To the unaware, the Yamanaka transcription factors, Oct4, Sox2, Klf4 and cMyc, were originally pioneered over 15 years ago by Nobel Prize-winning Japanese scientist Dr Shinya Yamanaka.
At the time, he had discovered that adding the four gene-regulating proteins to cells could allow them to be reprogrammed to return to a younger and more adaptable form dubbed embryonic stem cells.
These stem cells have the ability to transform into all cell types of the body due to their pluripotent nature.
In the most recent study, researchers tested variations of cellular rejuvenation approach in healthy animals as they aged, over long periods.
A group of mice received regular doses of the Yamanaka factors from the time they were 15 months old until they were 22 months old -- equivalent to 50 to 70 in human years.
Another mice group received the same from 12 through 22 months equivalent to 35 to 70 in human years, whereas a third group was treated for just one month at the age of 25 months, the equivalent to 80 in human years.
Compared to control animals, researchers saw no blood cell alterations or neurological changes in the mice who were recipients of the Yamanaka factors. There were also no cancers in any of the groups.
Looking at normal signs of ageing in the animals that underwent the treatment, they found that the mice resembled younger animals.
Both in kidneys and skin, epigenetics of animals with Yamanaka factors closely resembled epigenetic patterns evident in younger animals.
To understand if reprogramming can reduce tissue fibrosis the team analysed tissue accumulation in a skin wound after healing.
Researchers saw an increase in collagen deposits in the wound area of old untreated mice, whereas, in the long-term, partially reprogrammed mice, fibrosis in the wound area was low and similar to that in young mice.
Even the metabolic molecules in the blood of treated animals didn’t show age-related changes.
These changes were observed in mice treated for seven or ten months with the Yamanaka factors but not in those that were treated for just one month.
Also, these changes weren't very evident midway through their treatment, indicating that the treatment doesn’t just pause ageing but actively turn it backwards.
However, researchers claim more research is needed to differentiate the two.