Surprising Discoveries on Rejuvenation Elixirs: Platelet Factor 4

Monday - August 21 2023, 08:05 UTC - 1 year ago

Scientists have uncovered a startling discovery concerning the interplay between the brain, body, and blood, and its potential implications on longevity research: platelet factor 4, a protein produced in the body since childhood, is the key to regaining cognitive functions of memory, learning, and reasoning that fade with age. Early testing on mice has revealed promising results, and clinical trials on humans suggest PF4 may prove itself to be a revolutionary elixir for treating age-related ailments such Alzheimer's, stroke, and brain injury.

All right people, let’s do this one more time.

If you’ve been following longevity research, you already know the story: young blood, either directly infused or injected into old mice, restores multiple organ functions to their younger selves and lengthens lives.

Muscles regenerate. Heart tissues regain their strength. Brain regions critical for learning and memory fire back up, so that treated elderly animals learn and remember new environments faster and better than similarly aged peers.

While far from the proverbial "fountain of youth," the therapy has captured the interest and imagination of scientists and entrepreneurs alike. Clinical trials are in the works for Alzheimer’s disease. Commercial companies are offering the experimental infusions to those with the will—and the wealth—to test on themselves. To be very clear: treatment data on humans are scant. Enthusiasm, however, is reaching an all-time high.

Hype aside, a core question remains: Why does the therapy work in mice? What’s the component that turns a young animal’s blood into a rejuvenating elixir? .

This week, a team led by Saul Villeda at the University of San Francisco discovered a surprising candidate: platelet factor 4 (PF4). The protein’s not a stranger to science or life—your body likely produced a bunch as a kid when limping back home with a scraped knee. PF4 is part of the blood system that seals broken blood vessels and helps blood clot after injuries.

The new study, published in Nature, showed that the unassuming protein is far from a one-trick pony. Rather than a simple protein cog in the body’s wound-healing machine, PF4 also acts as an ambassador between the brain and the immune system. When young, the protein "gatekeeper" tunes down inflammation and helps maintain the brain’s cognitive functions.

Unfortunately, PF4 levels in the body nosedive with age. The drop incites a spark of inflammation in the brain’s "memory center"—the hippocampus—and hampers the neurons’ ability to communicate. Neural networks misfire. As does memory: an aged animal struggles to remember new places or learn new tasks.

It’s not all bad news. In one test, a jab of PF4 partially reset the body’s immune system, lowering levels of proteins that promote inflammation, and boosted cognition in elderly mice.

"I found it super surprising," Villeda told Singularity Hub. "Normally I think of platelets as more of supporting players, but here…[they’re] active drivers of cognitive rejuvenation." .

"The therapeutic possibilities are very exciting," said longevity researcher David Sinclair at Harvard University, who was not involved in the study.

Brain, Body, Blood .

The brain is protected by a cellular wall called the blood-brain barrier, which generally prevents large molecules from seeping from the blood into brain tissue. However, our noggins constantly talk with the rest of the body through smaller chemical messengers in the blood.

It sounds strange, but blood carries a wealth of chemical informants that brief the brain on the body’s status—hunger, heat, stress. In turn, these messengers also regulate neural network activity and even the birth of new neurons in the bran. The type and volume of chemical transmitters largely dictate how white or gray matter will develop and serve central functions in modulating body metabolism, behavior, and even cognitive processes.

Researchers led by Saul Villeda from the University of San Francisco have unveiled a new discovery within the field of longevity research: a protein known as platelet factor 4 (PF4), produced within the body since childhood and long thought to simply be part of the blood system that seals broken blood vessels and aids blood clotting, may actually be the key to regaining the cognitive functions of memory, learning, and reasoning that diminish with age due to lowered levels of the protein. Tests conducted on aged mice have already proven promising, but the most exciting evidence is the current clinical trials on humans that suggest PF4 could be a revolutionary elixir for counteracting age-related ailments such as Alzheimer's disease, stroke, brain injury, and chronic inflammation.

Beyond the potential therapeutic effects, the discovery of PF4 could also pave the way for understanding the intricate relationship between the brain, body, and blood, with implications on how white and gray matter grows and influences both cognition and metabolism. The research suggests that in addition to administering the protein in form of a single injection, drugs could eventually be developed to manipulate the production of PF4 within the body, proffering a safe, relatively cost efficient, and non-invasive course of treatment for elderly individuals looking to reap the benefits of a youthful mind.