It's
not quite the mythical fountain of youth but it is, perhaps, a start:
Scientists have managed to engineer human skin cells to reverse 30 years
of aging, resetting them to a much more youthful state in terms of
certain molecular measurements.
While
it's very early days for the research – so we shouldn't get carried
away too quickly – the technique could play a major part in efforts to
produce rejuvenative medicine that's able to undo some of the damaging
consequences of our bodies getting older.
What
makes the research particularly notable is that the skin cells were
reprogrammed to be biologically younger while still keeping some of the
functionality that made them skin cells in the first place.
Collagen production (in red) being restored in cells after reprogramming. (Fátima Santos, Babraham Institute)
The process used here builds on the Nobel Prize-winning work of Shinya Yamanaka in 2007, where Yamanaka was able to turn normal cells with a specific function into stem cells that can develop into any type. This meant, however, that the cell would lose its specific identity.
"Our
understanding of aging on a molecular level has progressed over the
last decade, giving rise to techniques that allow researchers to measure
age-related biological changes in human cells," says biologist Diljeet Gill from the Babraham Institute in the UK and the study's lead author.
"We were able to apply this to our experiment to determine the extent of reprogramming our new method achieved."
The
new method, dubbed 'maturation phase transient reprogramming', works
more quickly (13 days, compared to 50 in the Yamanaka team's
experiments) and stops before the stem cell state is reached, allowing
the cell to retain its original identity and function.
A
variety of measures, including the epigenetic clock (chemical tags that
indicate age) and the transcriptome (gene readings produced by cells),
were used to confirm that the skin cells had indeed been rolled back in
biological age by three decades.
Collagen production
is a key function of skin cells – useful for structuring tissue and
healing wounds – and the youthful cells were observed to be still
pumping the stuff out. In fact, they were producing more collagen than
control skin cells that hadn't undergone the reprogramming process, and
showed signs of being able to heal wounds more quickly.
"We
have proved that cells can be rejuvenated without losing their function
and that rejuvenation looks to restore some function to old cells," says Gill.
"The
fact that we also saw a reverse of aging indicators in genes associated
with diseases is particularly promising for the future of this work."
As
of yet, the scientists don't fully understand how the mechanism behind
maturation phase transient reprogramming works, but they think that
certain key parts of the genome, which help controls cell identity,
might be able to escape the reprogramming.
There are a huge number of age-related health issues to tackle as we get older – from heart disease to Alzheimer's –
and further in the future, the research that's been outlined here could
be useful in finding ways to tackle the progression of these issues.
One
of the next steps will be to try and apply the techniques used here to
other types of cells in the body, and to make sure the processes are
completely safe before moving them out of the lab and into clinical trials.
"Eventually,
we may be able to identify genes that rejuvenate without reprogramming,
and specifically target those to reduce the effects of aging," says molecular biologist Wolf Reik from the Babraham Institute.
"This approach holds promise for valuable discoveries that could open up an amazing therapeutic horizon."
The research has been published in eLife.