Vol. 24, Issue 2: Spring 2017

Making rejuvenation possible: How the development of proteins in the blood can be the root cause for age related diseases

Chelsey Campillo Rodriguez

Present day neuroscientists are still trying to figure out the underlying mechanisms of age-related diseases. Such conditions can lead to neural damage in the brain, as well as tissue and organ failure. In 2005, the Conboy lab at UC Berkeley published an article in Nature establishing the notion that “young” blood, or blood extracted from young adults, can help delay the progression of aging. However in the November 2016 issue of Nature Communications, the group identified a probable root cause for aging: inhibitory molecules present in “old” blood.

In their 2005 study, the team led by Drs. Irina and Michael Conboy, conducted an experiment called heterochronic parabiosis. This process consists of surgically joining two animals, mice in this case, so that they would exchange and share blood. The group’s findings supported the hypothesis that blood from young individuals contain rejuvenating properties that can help prevent age-related impairments. In order to further investigate this hypothesis, the team developed and used a new system called “heterochronic blood exchange” instead of parabiosis. Using heterochronic blood exchange between young and old mice was seen as advantageous because in parabiosis not only do animals exchange blood with one another, but they also share organs. With heterochronic blood exchange, on the other hand, the animals are not sutured together. Instead, the pumping and exchange of “young” and “old” blood are controlled by a computer; thus, this new method of exchanging large amounts of blood is not as physically inhibiting as heterochronic parabiosis. Because the young and old organisms are not sutured together, the scientists were able to control blood circulation and precisely measure the responses of older mice to the transfusion of “young” blood. In the 2016 experiment, the blood transfusion occurred until an old mouse shared half of its blood with a young mouse, and vice versa. Their results showed that older mice that received “young” blood exhibited slight improvements in tissue and brain cell development in comparison to old mice who did not receive a transfusion. This new technology has also proved to work faster than heterochronic parabiosis. In the 2005 paper, the Conboy lab found that the effects the blood exchange had on the organisms took about 2 weeks to occur. This time period is mainly due to the animals having to adjust to being surgically joined together. In contrast, since the mice were able to move freely with the heterochronic blood exchange technique, it took just about 24 hours to demonstrate any changes in mice.

In addition to demonstrating the benefits to using heterochronic blood exchange, the authors revealed potential key molecules that play a role in age processes. After injecting young mice with the blood extracted from older mice, the authors observed the behavior which resulted from the circulation of “old” blood. More specifically, their experiment showed a reduction in strength and growth of new liver and brain cells in the young mice. As a result, the scientists were able to reveal that it is not “young” blood that contains rejuvenating properties, but rather it is “old” blood that contains proteins which progress aging. These inhibitors are yet to be identified for the development of age-related disease treatments. However, this study is a key step in discovering out the root cause for diseases that lead to memory-impairment and organ and tissue failure. Detrimental diseases such as Parkinson’s, Alzheimer’s, and cardiovascular disease can be treated if the molecular inhibitors are removed.

About the Author

Chelsey Campillo is a third-year undergraduate student from Maryland. She is majoring in Molecular and Cell Biology, with an emphasis in Neurobiology. She loves learning about anything related to the human brain, and hopes to get her PhD in neuroscience.