It seems that humans have always been fascinated by the concept of anti-aging. In the 1950s, scientists conducted an interesting yet weird experiment in which they connected the circulatory systems of old and young mice. They found that this resulted in rejuvenation in the elderly animals. Following this initial experiment, many labs have begun their own research to identify molecules and factors in the young blood that can explain these results. A recent study released by a research group from Harvard University suggests that there is an anti-aging protein that was previously dismissed.
New Findings & Previous Studies
Amy Wagers, Harvard stem cell biologist, Richard Lee, a cardiologist at the Brigham and Women’s Hospital in Boston, and their fellow researchers have published a study on GDF11, a protein, which might explain the beneficial effects of young blood. They found that levels of GDF11 naturally drop in mice as they get older and injecting elderly mice with this protein can reverse aging effects, particularly in the heart. The protein injection appeared to reverse some of the age-related thickening of the cardiac muscle. They also reported that this protein had beneficial effects on general musculature and the brain.
A different group of researchers in the Novartis Institutes for Biomedical Research, led by muscle disease researcher David Glass, reported that the Harvard team had utilized an inappropriate assay. They stated that the antibody utilized by the Harvard team also detected levels of a different protein, myostatin, also known as GDF8, which is similar in structure but has a different impact. GDF8 hinders muscle growth. The Novartis group used a different assay which found completely opposite results. They found that GDF11 levels actually increase as mice aged, and GDF11 injections inhibited muscle regeneration in young mice.
To counter the argument made by the Novartis group, the Wagers and Lee group stated that the assay the Novartis group utilized was also inappropriate. They reported that the assay used actually focused on detecting immunoglobin levels, another protein whose levels rise as mice age. The Novartis assay’s results were misunderstood, and the Wagers group reports that the results between the two groups were actually similar. This was because mice, who lacked the gene for immunoglobin also tested negative for the active forms of both proteins, GDF11 and GDF8.
Another recent study found that GDF11/8 levels declined as people age, and the levels of both of these proteins were low in individuals affected by cardiovascular disease. These findings put together suggest that their initial claims might be correct; GDF11 may have a role in anti-aging. The Wagers and Lee group also disputed findings from a different study done by a research group at Temple University that showed that GDF11 injections had no effect on heart thickness in elderly mice. They attributed this finding to the variance of commercially purchased GDF11. Wagers suggests that there is a variance in the activity and level of the protein when it is commercially purchased. This variability might have led to these results, although this group utilized the same dosages as the Harvard group.
So what does this mean?
It seems the initial research done by the Harvard group might have accurately assessed the role and potential of GDF11 in anti-aging. They further supplemented the initial research with new results showing that daily GDF11 injections led to heart muscle shrinkage in mice of all ages. All of the groups involved in this body of research are not trying to prove each other wrong. They are simply trying to perform proper research and identify whether or not this protein actually does have a role to play in anti-aging, particularly of the cardiovascular system. It seems that GDF11 may play a role but it is still yet to be determined whether or not it does and what that potential role is.