27 December 2023
Scientists discover a common protein that links young blood, the anti-aging hormone klotho, and exercise to improved brain function in older mice.
For years, researchers have observed that young blood, the anti-aging hormone klotho, and exercise have positive effects on brain function in older mice. However, the underlying mechanisms behind these improvements have remained a mystery. Now, a breakthrough study conducted by two research teams from UC San Francisco and a team from the University of Queensland has identified platelet factor 4 (PF4) as the common factor behind these three interventions. PF4, a small protein released by blood platelets, has been found to rejuvenate the aging brain and enhance the young brain’s capabilities. This discovery opens up new possibilities for developing therapies to restore brain function and potentially tap into the fountain of youth.
PF4 and Young Blood: Restoring Brain Function
In 2014, Dr. Saul Villeda and his team at UC San Francisco discovered that blood plasma from young mice could restore brain function in older animals. They found that young plasma contained significantly higher levels of PF4 than old plasma. Further experiments revealed that injecting PF4 into older animals had a similar restorative effect as young plasma. PF4 not only calmed down the aged immune system in the body and the brain but also improved memory and learning tasks in older animals. The immune system appeared younger, reducing inflammation and promoting brain plasticity. The researchers successfully reversed the brain function of 22-month-old mice, equivalent to humans in their 70s, to resemble individuals in their late 30s or early 40s.
PF4 and Klotho: Enhancing Brain Function
Dr. Dena Dubal, a neurology professor at UCSF, had previously shown that the hormone klotho could enhance brain function in both young and old animals. However, klotho injected into the body did not reach the brain. In the recent study, Dubal’s team discovered that PF4, released by platelets after an injection of klotho, played a crucial role in enhancing brain function. PF4 had a significant impact on the hippocampus, the region responsible for memory formation. It promoted the formation of new neural connections and improved cognitive function in both young and old animals. This finding suggests that there is potential for enhancing cognitive function even in young brains.
PF4 and Exercise: Countering Cognitive Decline
Exercise has long been known to have positive effects on brain health. Dr. Tara Walker and her team at the University of Queensland found that platelets released PF4 into the bloodstream following exercise. When tested independently, PF4 improved cognition in older animals, similar to the effects observed with young blood and klotho. This finding is particularly significant for individuals who may not be able to engage in physical exercise due to health conditions or age-related mobility issues. Targeting platelets to promote neurogenesis and enhance cognition could offer an alternative approach to counteracting age-related cognitive decline.
Conclusion: The discovery of platelet factor 4 (PF4) as a common factor behind the rejuvenating effects of young blood, klotho, and exercise on brain function in older mice is a significant breakthrough. The identification of this small protein opens up new avenues for research and potential therapies aimed at restoring brain function and combating age-related cognitive decline. Further studies will be needed to explore the translation of these findings to human subjects. Nonetheless, this research brings us one step closer to understanding the mechanisms behind brain rejuvenation and offers hope for a future where cognitive decline may be reversible or preventable.
