Scientists say mouse model might be the key for a true ‘fountain of youth’
FARMINGTON, Conn. — Scientists at the University of Connecticut have made a remarkable breakthrough in the quest for longer, healthier lives. In a major study, the researchers successfully extended both lifespan and healthspan in mice by targeting specific cells in their bodies. This exciting development brings us closer to the dream of not just adding years to life, but life to years.
The study, published in Cell Metabolism, focuses on cells that highly express a protein called p21. These “p21-high” cells accumulate in various tissues as we age and appear to contribute to age-related decline. By periodically eliminating these cells in mice, the scientists were able to extend the animals’ lives by an average of 9%. That’s equivalent to about seven human years. More importantly, the mice remained healthier and more physically capable throughout their extended lives.
The finding addresses a critical challenge in aging science: how to increase lifespan while simultaneously improving quality of life. Currently, there’s often a gap between how long people live and how long they live in good health. In some countries, life expectancy is increasing faster than healthspan, meaning people are living longer but spending more time in poor health.
Targeting p21-high cells in mice
What makes this study particularly noteworthy is the comprehensive way the researchers assessed the mice’s health. Instead of just measuring lifespan or looking at health at a single point in time, they tracked the mice’s physical function monthly until natural death. This allowed them to show that the treatment improved health throughout the entire remaining lifespan, not just temporarily.
To achieve these remarkable results, the researchers employed an innovative approach. They used genetically modified mice that allowed them to specifically target and eliminate the p21-high cells. These mice were designed with a genetic switch that, when activated, would cause p21-high cells to self-destruct. The scientists began their intervention when the mice were 20 months old, equivalent to about 60-65 human years.
Once a month, the researchers administered a drug called tamoxifen to the mice. In the treated mice, this drug activated the genetic switch, causing the p21-high cells to die off. Control mice received the same drug but lacked the genetic switch, so their p21-high cells remained intact.
Fountain of youth effect
The treated mice showed better grip strength, faster walking speeds, and lower frailty scores compared to untreated mice. They also had improved heart function, better glucose tolerance and insulin sensitivity, and healthier livers. All of these benefits persisted even into the final months of life, suggesting a true extension of healthspan.
Interestingly, the treatment didn’t seem to prevent any specific diseases. Instead, it appeared to slow down the overall aging process, leading to better health across multiple body systems. This aligns with the idea that targeting fundamental aging processes could be more effective than trying to treat individual age-related diseases one by one.
But the benefits didn’t stop there. The treated mice also showed improvements in several key areas of health:
- Better heart function: Echocardiograms revealed that the treated mice had stronger, more efficient hearts.
- Improved metabolism: The mice showed better glucose tolerance and insulin sensitivity, indicating healthier metabolism and potentially reduced risk of diabetes.
- Healthier livers: Blood tests showed lower levels of enzymes associated with liver damage in the treated mice.