Ageing process reversed by ‘young blood’
Three independent studies find that older mice can be rejuvenated by younger mice…
In the first study, researchers from Harvard University administered a protein (GDF11) found in young mice into older mice. This enabled the older mice to run for longer on a treadmill. Researchers also found that the treated mice had more branching blood vessels than the untreated mice.
Amy Wagers, Professor of stem cell and regenerative biology at Harvard University was involved in two of the three studies.
“These are the tissues that are really affected by advancing age,” said Wagers. “Changes in these tissues are responsible for the changes that people worry about the most — loss of cognition and loss of independent function.”
Wagers acknowledged that while there are many unanswered questions about the mechanisms of the protein and how to use it therapeutically, she is working to commercialise the discovery.
The study is not the first time this rejuvenating effect has been seen in mice. Previously, researchers stitched together the circulatory systems of pairs of old and young mice—a process called parabiosis—and found this had a significant impact on the cells within the older animals.
Dr Lee Rubin, director of translational medicine at the Harvard Stem Cell Institute found in a second study that after parabiosis there was an increase in how quickly new brain cells were created. He also noted that the branching network of the blood vessels in the brain increased.
The third study, carried out by researchers at the University of California, San Francisco, and Stanford, found changes in the activity of the genes that connected brain cells in the hippocampus—a memory centre.
Unlike the previous studies, the researchers did not use a specific protein, but instead gave older mice repeated blood transfusions from younger mice. The results showed an improvement in age-related memory in the older animals.
Saul Villeda, fellow at the University of California San Francisco, said that despite taking different approaches, the three studies corroborated one another.
Villeda said, “I’m really interested to see whether GDF11 accounts for everything, or whether it’s going to be a combination of factors that together has the full effect.”