As we age, our muscles and brain don’t retain their qualities that they did during youth. However, a recent study has shown that protein therapy can help restore muscles and brains to their former glory through therapy with the protein growth differentiation factor 11 (GDF 11). The study was led by Amy Wagers and Lee Rubin from Harvard’s Department of Stem Cell and Regenerative Biology (HSCRB) and Harvard Stem Cell Institute (HSCI) and the results were published in two papers that have both been published in Science.
The mice used in this experiment have the muscle and brain function that is equivalent to a 70 year old human. Concentrations of GDF 11 are much higher in younger mice than older mice, so the researchers sought to increase levels in older mice. In one of the studies, an older mouse was surgically connected to a younger mouse, allowing them to share a blood supply. The other study simply injected GDF 11 into the older mouse.
The primary effect of GDF 11 appears to be increased blood flow, and it was noted that the older mice who had elevated concentrations of GDF 11 were able to repair muscle damaged after injury. Not only was the improved vascularity shown to give the mice improved muscle function, but it also bolstered function in the region of the brain involved with olfaction, which is how we interpret smells. The brain was shown to have an increased amount of neural stem cells.
“This should give us all hope for a healthier future. We all wonder why we were stronger and mentally more agile when young, and these two unusually exciting papers actually point to a possible answer: the higher levels of the protein GDF11 we have when young,” Doug Melton, co-chair of HSCRB and co-director of HSCI said in a press release. “There seems to be little question that, at least in animals, GDF11 has an amazing capacity to restore aging muscle and brain function.”
Previous research with GDF 11 showed that it was able to confer rejuvenating properties onto the heart as well, making many hopeful that it could be used to treat diastolic heart failure; an irreversible and fatal heart condition. GDF 11 has been shown, however, that it is not heart-specific and could have widespread positive effects throughout the body.
If all goes well, Wagers and Rubin speculate that human trials of this therapy could begin in about 3-5 years. This would not just benefit the physical fitness of senior citizens, but may improve their mental faculties as well. The researchers speculate that drugs developed from this protein could be effective treatments against neurodegenerative diseases like Alzheimer’s and others where age is one of the largest factors.