A team of researchers from Harvard University, which included Lida Katsimoardi and Lee L. Rubin, conducted an experiment to test if young systematic factors could reverse the decline in the potential for neural stem cells in aging mice.
The team used a heterochronic parabiotic model, which is when two animals are joined together to share the same circulation system. First, the team used a 15-month-old mouse and joined it to a 2-month-old mouse. The findings showed that the old blood did not negatively effect the production of the neurons in the younger mouse. To see how an older mouse might affect the two-month-old mouse, the team used a 21-month-old mouse and joined it to a 2-month-old mouse. Their findings showed that the old blood negatively effected the production of new neurons in the young mouse, and the young blood of the 2-month-old mouse increased the production of neurons in the older mouse. This research shows that youthful blood can restore the potential of stem cells to differentiate in aging mice, and that there comes a certain point where aging blood can negatively effect the production of neurons.
The team also increased the amount of stem cells associated with aging mice’s smelling senses to see if the increased neural stem cells would lead to better abilities of smelling. The results were that aging mice were able to smell much better after the increase in neural stem cells to the olfactory bulb.
The researchers then created an angiogram, which is a three dimensional representation of blood vessels, to see if young blood factors can also reverse the decrease blood flow in aging mice. The heterchronic parabiosis model showed a tremendous increase in the blood vessel volume and the blood vessel branching in the aging mice. They also experimented with GDF11, a protein that inhibits the growth of nerve tissue, to see if it could also increase the generation of neurons in aging mice.
They injected GDF11 into 21-month-old mice and 23-month-old mice for four weeks to see the possible effects it could have on their blood vessels. The results showed that the volume of blood vessels in the GDF11 treated mice increased by 50%, and a specific neural stem cell called Sox2+ increased by 29%.
These new finds will lead to much more experiments in this field of rejuvenation of the vascular and neural systems of aging mice. This is just the beginning with these experiments. This can lead to new discoveries with certain diseases associated with old age in humans including Alzheimer’s. If these new discoveries can have the same effect in humans that it does in mice then new medicines and therapeutic treatments with aging-associated diseases can be manufactured. Hey, now Benjamin Buttons is not sounding that crazy anymore!
1- Aging vs. Rejuvenation. Digital image. Https://lucyhagger.wordpress.com. N.p., n.d. Web
2- "Growth Differentiation Factor." Http://www.ncbi.nlm.nih.gov/gene/10220. N.p., n.d. Web.
3- Katsimpardi, Lida, and Lee L. Rubin. "Vascular and Neurogenic Rejuvenation of the Aging Mouse Brain by Young Systematic Factors." Http://www.sciencemag.org. N.p., 10 Apr. 2014. Web.