Blood transfusions have long been recognized for saving lives, but recently several studies report that blood may also be the key to regaining youth. Researchers report that blood obtained from healthy young adults has the potential to rejuvenate adults suffering from age-related degenerative processes, including cognitive decline.
The first study — reported in Nature and authored by Saul Villeda, Ph.D., and colleagues — used a mouse model of heterochronic parabiosis. This technique, which has been used for more than a century, surgically combines the circulatory systems of animals of differing ages and evaluates how the systemic aspects of aging are impacted by the younger animal's circulatory processes.
What's unique about the Nature study is that the group demonstrated improvements in cognitive functions and memory. Earlier studies had demonstrated improvement in numerous other structures. The technique, however, has not been tried in humans.
An additional study using a mouse model found that injecting aging tissue with a component of blood that is lost with aging — growth differentiation factor 11 (GDF11) —remodels the tissue, giving increased function.
The team led by Francesco Loffredo, M.D., Ph.D., of the Harvard Stem Cell Institute and Cardiovascular Division of Brigham and Women's Hospital in Boston, found that the injections improve cerebral vasculature function and enhance neurogenesis. Loffredo also led a group that found that treating mice suffering age-related cardiac hypertrophy with GDF11 reversed the cardiomyopathy.
The use of GDF11 systemically also improves muscle structure and function in aged mice, as found by Manisha Sahin, PhD, of the Harvard Stem Cell Institute and Department of Stem Cell and Regenerative Biology located in Boston. The result for the mice is increased strength and increased endurance exercise capacity.
The transfusion of blood or blood components is not new. The first successful blood transfusion was performed by physician Richard Lower in 1665 in England, but it was not until 1901 that Austrian physician Karl Landsteiner isolated individual blood groups. This was followed by the ability to fractionate blood into components in 1940.
Today, blood has four components used in transfusion — red blood cells, platelets, plasma and cryoprecipitate. It is conceivable that human blood has the component proteins similar to those demonstrated in the mice studies. This leads to potential treatments for debilitating age-related diseases such as Alzheimer's disease and cardiomyopathies.
