Past research has shown that blood from younger animals can have regenerative effects on older animals, but this has not been confirmed in humans. A recent study examined the effects of using umbilical cord blood plasma as a treatment to restore cognitive function in mice and examined the mechanisms behind this interesting phenomenon.
As we age, we gradually lose function and activity in many aspects of our bodies. There is a significant decline in the function of our brains; one region known to be affected by age is the hippocampus, which is responsible for memory and learning. Scientists have shown that blood from young animals can counteract age-related changes in older animals. However, it is not known whether these effects also occur with human blood plasma (blood, but with red blood cells removed). A group of researchers hypothesized that human umbilical cord plasma can restore hippocampal function. They tested their hypothesis on mice and an article describing their findings was recently published in Nature.
Blood plasma was collected from elderly individuals, young adults, and the umbilical cords of newborns to compare the contents within the plasma. There were distinct differences in the plasma from different age groups, with varying levels of proteins and factors. Next, they performed experiments using mouse models to see the direct effects of human umbilical cord plasma in an animal setting. Older mice had impaired learning and memory performance when compared to young mice, which was tested by using a maze and a conditioning test. Old mice were treated with plasma from the 3 age groups, and then their hippocampi were processed and screened for differences in gene expression. Umbilical cord plasma induced significant increases in the expression of a group of genes that are associated with memory. A separate mouse model was able to confirm that umbilical cord plasma could enhance brain activity in mice. Interestingly, when the old mice were treated with the umbilical cord plasma, they performed significantly better in the maze and conditioning tests.
Using various screening and discovery methods to compare young and old plasma, they determined certain proteins could be playing a role in this phenomenon that they have observed. Further investigation showed that there were higher levels of a protein called TIMP2 in umbilical cord blood. When they gave mice more of this protein, their performance on the learning and memory tests improved significantly. Furthermore, to examine how important this protein was in the regenerative plasma treatments, they removed TIMP2 from umbilical cord plasma, then treated old mice with the plasma lacking TIMP2. The regenerative effects of the plasma were no longer seen, suggesting that TIMP2 played a very important role in its beneficial effects.
Overall, this study showed that umbilical cord plasma treatment improved cognitive function related to the hippocampus. They also examined how the plasma produced this regenerative effect and discovered a new role of the TIMP2 protein. This study provides support for potential regenerative treatments that involve TIMP2 to treat older patients whose hippocampi have impaired function. However, more research is needed to better understand the role of TIMP2 and how it produces beneficial effects in the brain.
Written By: Branson Chen, BHSc