Scientists discover potential secret to reversing aging

Ancient viruses, whose DNA has hitchhiked within the human genome for millennia, may be the cause of many age-related conditions.

Scientists have proven for the first time that they can use this viral DNA — known as 'retroelements' — to predict the age of human cells with 'high accuracy.'

In recent years, this seemingly inactive 'junk' DNA from retroelements has been linked to everything from sleep patterns and memory formation to bipolar disorder.

Armed with their new ability to track a person's age via this ancient viral DNA, the scientists now plan to investigate whether new antiviral treatments could reverse the conditions of aging, by deactivating the worst of these viral 'retroelement' genes.

The new research harnesses previously unknown features of this ancient viral DNA, creating a biological clock to track a person's age from the DNA's chemical changes.

And the researchers now believe that new antiretroviral therapies, similar to those used to fight the HIV virus and AIDS, might one day help reverse the signs of aging.

'Our findings indicate that retroelement clocks capture previously undetected facets of biological aging,' said study co-author Dr Michael Corley, an assistant professor of immunology at Weill Cornell Medicine in New York. 

Dr Corley emphasized that the new study's new age-calculating technique, named 'Retro-Age' by his team, 'may open the door to future treatments for these and other age-related conditions.'

At the heart of their new age-detection method is a process called 'methylation,' in which parts of a DNA strand are swapped with a mixture of carbon and hydrogen atoms called a 'methyl group' — a chemical tag that then activates that gene. 

Changes in these 'chemical tags' on some ancient viral 'retroelements' appear to be linked to inflammation, instability within the genome and some age-related diseases.

'The reactivation of specific retroelements increases with age, potentially leading to biological hallmarks of aging,' Dr Corley said.

The Weill Cornell researcher, who specializes in such 'epigenetic' markers, also noted that 'cellular senescence,' or the phenomenon of aging cells ceasing to multiply via cell division, also appears to be linked to this activated ancient viral DNA.

Treatments that could halt this ancient viral DNA from becoming active, the team has theorized, could wind back the clock on many physical symptoms of aging — from weathered skin to slowed muscle growth — though it may not cure aging itself.

The new research, published this month in the journal Aging Cell, utilized an AI machine-learning model created by Kentucky-based medical firm TruDiagnostic to track DNA methylation.

The firm's model was trained on the DNA data of about 12,670 people between the ages 12 and 100.

Past research has shown that as much as 8 percent of the human genome is made up of viruses, like the ancient viral retroelements at the heart of the new study.

Dr Corley and his colleagues' 'Retro-Age' technique showed promise in two areas.

First, it helped them to more precisely identify and document when the so-called biological and chronological age of a person diverged. 

Chronological age is measured simply as the number of years they have been alive.

While biological age is how old cells appear based on their health and performance.

But, secondarily, their work appeared to uncover an anti-aging effect tied to virus-fighting antiretroviral drugs, like those used to treat people with HIV/AIDS.

The team now hopes to conduct new studies to determine if the effect from those treatments could have a similar anti-aging effect on individuals who are not already coping with HIV or another immunosuppressing virus.  

'Whether antiretroviral therapy can be used as therapeutic to improve health and increase lifespan,' they wrote in the new study, 'warrants further investigation.' 

Their next step, the researchers said, was to conduct a long-term study of those who receive such therapies to protect themselves from HIV in advance, before any potential future exposure, via treatments known as pre-exposure prophylaxis (PrEP).  

PrEP deploys antiretroviral drugs, sometimes as a pill like tenofovir disoproxil fumarate, preemptively to cut down the risk of an HIV infection before it happens.

'Analysis of the effects of pre-exposure prophylaxis (PrEP) [...] on retroelement-based epigenetic age.' the Weill Cornell team wrote, 'can uncover potential effects of antiretroviral drugs in HIV-negative people on aging.'

Study co-author Dr Lishomwa Ndhlovu, also at at Weill Cornell, told reporters that the team also plans to investigate new treatments for age-related diseases by testing the epigenetic states of key suspect retroelements found within the human genome.