With
age comes experience. And with experience come sore backs, tired bones,
and increased risks from a large number of diseases.
Scientists
have long been trying figure out how to stop these aches and pains in
our twilight years, and to make us live longer and healthier lives at
the same time.
While
it's likely a long way off from being ready for humans, a new study
investigating the long-term 'partial reprogramming' of cells in mice
appears to have produced some very intriguing results.
"We are elated that we can use this approach across the life span to slow down aging in normal animals," says senior author and Salk Institute developmental biologist Juan Carlos Izpisua Belmonte. "The technique is both safe and effective in mice."
The
team found that tissues in the kidney and skin of the mice were
'rejuvenated' – meaning that expressions of genes which cause
inflammation, cell death, and stress response were lowered in the
treated animals. The skin was even able to proliferate more and scar
less – the opposite of what usually happens in older age.
Plus,
the animals' epigenetic clocks – a measure of the patterns of DNA
methylation levels attributed to aging – seemed to be wound back.
"In
addition to tackling age-related diseases, this approach may provide
the biomedical community with a new tool to restore tissue and
organismal health by improving cell function and resilience in different
disease situations, such as neurodegenerative diseases," Izpisua Belmonte says.
That's
a long way away yet, as this research has only been conducted in mice
thus far, but the treatment appears to be safe and effective in the long
term, and could – hypothetically speaking – one day help humans stave
off some of the worst parts of aging, if the effects can indeed be
replicated in people.
In the study, the researchers experimented with four well-known proteins that regulate the expression of DNA – Oct4, Sox2, Klf4 and c-Myc – known collectively as "Yamanaka factors" after the man who pioneered the technique in stem cells.
Although this technique can be used to turn adult cells back into stem cells, the current team had previously shown it can also be used to 'partially reprogram' the cells by reverting them into a more youthful state, but not completely becoming a stem cell again.
If
the same thing were done to enough cells in an animal's body, this
could potentially make the whole organism's body clock seem younger.
With
this already known, the researchers wanted to look at what would happen
to these mice when the Yamanaka factors were applied longer term.
In
the new research, the factors were used in three different ways. The
first trial was short: A group was treated with the factors for one
month when they were 25 months old (equivalent to around 80 years old in
humans).
The
second and third groups had longer-term treatments. One received
regular doses from 15 to 22 months (equivalent to ages 50-70 in humans),
and the other received regular doses from 12 to 22 months (ages 35-70
in humans).
The
mice treated for just one month didn't show any of the age-reversing
qualities, but the two longer treatment groups showed signs of
rejuvenation without any increased risk of cancer or other health problems.
"Overall,
this study provides provocative hints that long-term partial
reprogramming holds promise as an intervention that might restore and
rejuvenate the functions of some tissues," researchers Arianna Markel
and George Q. Daley from Boston Children's Hospital, who weren't
involved in the study, explain in an accompanying commentary on the research.
"It
is especially notable that partial reprogramming successfully elicits
systemic transcriptomic, metabolomic, and lipidomic changes, and alters
the epigenetic clock. Moreover, observing these results in a normally
aging mouse model provides further evidence that this approach may be
beneficial beyond disease states."
Although
the method is likely many years away from providing a human 'fountain
of youth', it's still an exciting development in anti-aging science, and
one that just might help ease the pain and damage of getting old one
day.
The research has been published in Nature Aging.