The plot of all vampire stories rests on one basic assumption – the blood of humans younger than it keeps the vampire young as well. It has long been known that injecting the blood from a young muscle can restore youthful features in an aging one. What has not been known is what specific element of that blood causes the regeneration … until now. Scientists at the University of Pittsburgh have isolated a longevity protein with a vampiric name – Klotho – and it just might provide what some Silicon Valley billionaires are searching for … the transfusion of youth.
“We wondered if extracellular vesicles might contribute to muscle regeneration because these couriers travel between cells via the blood and other bodily fluids. Like a message in a bottle, EVs deliver information to target cells.”
In a press release on her paper that sounds more like a treatise on transportation,” lead author Amrita Sahu, postdoctoral fellow in the Department of Physical Medicine and Rehabilitation at the University of Pittsburgh, describes her team’s research on aging mice which was published this week in Nature Aging. “Extracellular vesicles” or EVs are “shuttles” and senior author Fabrisia Ambrosio, director of rehabilitation for UPMC International and associate professor of physical medicine and rehabilitation at Pitt, wondered if they could carry something besides information.
The researchers had a shuttle and a freeway system – what they needed were some old cities to rejuvenate. If this is a lab, those would be mice. They collected blood serum – what’s left after removing blood cells and clotting factors – from young mice and injected them into old mice. When the old mice showed muscle regeneration, they wondered how the serum targeted the area and what shuttle passenger responsible.
When the team removed the EVs, the rejuvenation stopped. That identified it as the vehicle. Inside of them, they found the anti-aging protein Klotho, which contained genetic instructions, or mRNA. Like one of those new smartphone apps, they tracked the EVs and saw them enter muscle progenitor cells, a type of stem cell responsible for regeneration. They then compared the EVs of young and old mice and found that the old EVs had less Klothos than those in younger mice. Loading the EVs up with young Klothos gave the old mice younger muscles. Time to drop the mic?
“EVs may be beneficial for boosting regenerative capacity of muscle in older individuals and improving functional recovery after an injury. One of the ideas we’re really excited about is engineering EVs with specific cargoes, so that we can dictate the responses of target cells.”
Not quite. While this works for muscle cells, there’s more to aging – like cognitive degeneration. Ambrosio and coauthor Radosveta Koldamova, professor of environmental and occupational health at Pitt’s Graduate School of Public Health, have received a grant to study how EVs can deliver passengers that reverse age-related declines in cognition.
Does this prove vampires have the right idea … or should we accept the facts and just accept growing old gracefully?
And would Klothos and Evie make great names for a vampire couple?