Written by: Will Borges '24
Edited by: Melinda Li '22
When Spanish explorer Juan Ponce De Leon fantasized about finding the fountain of youth in the 16th century, he probably never pictured that the mystical source of eternal youth would be closer to Count Dracula than any ornate fountain. In the centuries that followed, scientists and physicians instructed patients to sleep with young virgins, bathe in blood, and drink blood to maintain a youthful glow . Although rudimentary, approaches of the past may have had some ultimate merit, as we will soon come to realize. Fast forward to the 21st century and we encounter a new emerging medical technology referred to as heterochronic parabiosis, also known as the vampire cure.
“Heterochronic” refers to organisms of different ages and “parabiosis” is a stomach churning research technique that involves surgically stitching two organisms’ circulatory systems together. Therefore heterochronic parabiosis is a technique by which the circulatory systems of an older and younger organism are stitched together. This is a modern anti- aging therapeutic technique straight out of science fiction with the potential to rejuvenate the body and maintain an eternally youthful glow.
Who came up with this and why?
Parabiosis was invented in 1864 by physiologist Paul Bert to see whether a shared circulatory system could be created . Later in the early 1900s, Clive McCay, a biochemist at Cornell University, picked up where Bert left off and applied the technique to the study of aging. However, by the 1970s parabiosis had lost its popularity because organisms that were joined often died within two weeks of being stitched from a condition called parabiotic disease .
This brings us to 2005, when Irving Weissman and Thomas A. Rando from Stanford University resurrected parabiosis to study blood stem cells . The data published in their 2005 paper revealed that circulating factors controlled molecular pathways critical in inhibiting or activating tissue-specific precursor cells . They also noted that the internal environment of a young animal is one that promotes successful regeneration of liver and muscle tissue, whereas that of an older animal either fails to promote or actively inhibits regeneration . In a 2010 follow-up paper, a team at Harvard led by Dr. Amy Wagers published data suggesting that the rejuvenating effects of a young circulatory system on blood stem cells can be triggered by signaling from rejuvenated osteoblastic cells, a cell type responsible for bone formation in the bone marrow . This paper was retracted by three of the authors in 2010 because it was found that the first author manipulated images. However, this did not discourage the team from continuing research in this area. In a number of follow-up papers, the team identified GDF11, Growth Differentiation Factor 11, as a blood factor with a role in reversing age-related heart disease, promoting the growth of new blood vessels and neurons in the brain, and engaging stem cells to regenerate muscle at injury sites . Today, many researchers are on the hunt for more mysterious blood factors that may play a role in multiple diseases of aging and ultimately serve as the swiss army knives of anti-aging therapy.
Where does this leave us?
As you can already tell, the hunt for eternal youth is something that makes a lot of scientists, billionaires, and celebrities very enthusiastic. If they could cheat death and look good while doing it, why shouldn't they? While it is true that this technology has the potential to fundamentally change humanity for the better, it is also dangerous if not used in the right way. Consider the evolutionary role of aging and death for a moment. Aging and death recycles older generations to make room for newer generations. If humans could live 150+ years, Queen Victoria would still be reigning in England and the world would be significantly less accepting and diverse. In addition, inequality in access might be an issue, as with any novel therapeutic. This therapy is likely to be expensive, and if only the rich and powerful have access this may add an element of biological justification to inequalities that exist today in the world. “The rich are rich because they live forever and the poor die” could be a saying that we might hear in the near future if we are not careful with this technology.