People with an older biological age than their chronological age may be more at risk for dementia. (© svetazi - stock.adobe.com)
NEW YORK — Researchers have discovered that dormant viral remnants buried deep within our genetic code could be the key to understanding and potentially reversing the aging process. These ancient viral hitchhikers, known as retroelements, have been hiding in plain sight for millions of years. Now, scientists have found a way to use them as a biological clock, offering new insights into how we age and opening doors to potential anti-aging treatments.
The human genome is a vast landscape of genetic information, much of which was once considered “junk DNA” with no apparent purpose. However, hidden within this genetic wasteland are the ghostly remnants of ancient viruses that infected our ancestors long ago. In fact, prior research shows that up to 8% of the human genome is made up of viruses.
These viral fragments, called retroelements, make up a significant portion of our DNA and have been passed down through generations. While most of these retroelements lie dormant, some can become active as we age, potentially contributing to age-related diseases and the aging process itself.
Now, a team of researchers at Weill Cornell Medicine has developed a new way to measure biological age by looking at specific patterns in these retroelements. According to their study in Aging Cell, they created what they call “retroelement-based epigenetic clocks” (or “Retro-Age”) – a method of estimating a person’s biological age by examining chemical changes in the DNA of these ancient viral remnants. These clocks proved to be surprisingly accurate, often matching or outperforming existing methods of measuring biological age.
“Now, with Retro-Age, we have greater insight and a fresh perspective into the aging process and a potentially powerful tool to predict biological age,” says first author Dr. Lishomwa Ndhlovu, the Herbert J. and Ann L. Siegel Distinguished Professor of Medicine and professor of immunology in medicine in the Division of Infectious Diseases at Weill Cornell Medicine, in a media release.
What makes this discovery truly exciting is its potential implications for understanding and potentially reversing the aging process. The researchers found that their retroelement-based clocks could detect accelerated aging in people with HIV, a condition known to speed up the aging process. More intriguingly, they observed that antiretroviral drugs used to treat HIV appeared to slow down or even reverse this accelerated aging.
“The reactivation of specific retroelements increases with age, potentially leading to biological hallmarks of aging such as inflammation, cellular senescence and genomic instability,” says corresponding author Dr. Michael Corley, assistant professor of Immunology in Medicine in the Division of Infectious Diseases at Weill Cornell Medicine. “Our findings indicate that retroelement clocks capture previously undetected facets of biological aging and may open the door to future treatments for these and other age-related conditions.”
This finding raises an intriguing possibility: could drugs that target these ancient viral elements in our DNA be used to slow down aging in everyone, not just those with HIV? While it’s too early to say for certain, the research opens up new avenues for exploration in the field of anti-aging medicine.
The study also revealed that the retroelement-based clocks could detect rejuvenation in cells that had undergone a process called “transient reprogramming” – a controversial technique that aims to reset cells to a younger state. This suggests that these clocks might be useful tools for evaluating the effectiveness of potential anti-aging treatments.
Perhaps most surprisingly, the researchers found that similar retroelement-based clocks could be created for other mammals, from mice to elephants. This hints at a universal mechanism of aging across different species, potentially linked to these ancient viral remnants in our DNA.
As we unravel the mysteries of these genetic time capsules, we may be getting closer to understanding the fundamental processes that drive aging. While the fountain of youth remains a distant dream, this research offers a new perspective on the aging process and may lead to novel strategies for promoting healthier, longer lives.
Paper Summary
Methodology
The researchers started by identifying specific spots in our DNA that corresponded to these ancient viral remnants. They then looked at chemical changes, called methylation, at these spots in DNA samples from thousands of people of different ages. Using machine learning, they created a model that could predict a person’s age based on these chemical patterns. They tested their model on various datasets, including samples from people with HIV and cells that had undergone rejuvenation treatments.
Key Results
The retroelement-based clocks were highly accurate in predicting chronological age, often performing as well as or better than existing biological age predictors. They detected accelerated aging in people with HIV and showed that this acceleration could be reversed with antiretroviral treatment. The clocks also picked up on rejuvenation in cells that had undergone experimental anti-aging treatments. Importantly, similar clocks could be created for other mammal species, suggesting a universal aging mechanism.
Study Limitations
The study primarily focused on blood samples, so it’s unclear how well these clocks work in other tissues. The researchers also note that while their clocks can measure aging, they don’t necessarily explain why aging occurs. Additionally, the study doesn’t prove that targeting these retroelements can actually slow down aging in humans – that would require further research.
Discussion & Takeaways
This study suggests that ancient viral elements in our DNA play a more significant role in aging than previously thought. It offers a new tool for measuring biological age and opens up new possibilities for anti-aging research. The fact that similar clocks work across different mammal species hints at a universal aging mechanism linked to these retroelements. While we’re still far from a “cure” for aging, this research provides new directions for future studies and potential treatments.
Funding & Disclosures
The study was funded by grants from the National Institutes of Health. Some of the authors, including Dr. Ndhlovu, are listed as co-inventors on pending patents related to this work. Additionally, some authors have served as scientific advisors for pharmaceutical companies, though this was unrelated to the current study. Three of the authors are employees of TruDiagnostic, a company that offers epigenetic testing services.
