Can the Secretome of Mesenchymal Stem Cells be Used to Effectively Treat Alzheimer’s Disease?

Alzheimer’s disease is one of the many forms that dementia can come in and is the most prevalent form of dementia in the elderly population. Alzheimer’s results in clots formed in the brain due to a product known as beta-amyloid. Alzheimer’s also causes the brain to be continually inflamed which causes toxins to be released and leads to the brain being damaged. The disease targets a large number of biological systems, therefore, treatments that target multiple different systems can be beneficial. One such treatment is the use of mesenchymal stem cells, which are one of the initial cells present during embryonic development that can become many different types of cells through further development. There are many difficulties associated with the use of mesenchymal stem cells ergo this experiment uses their secretome, which is something that holds biological components and will release them when exposed to an environment that is injured. The idea was to use the mesenchymal secretome to reduce inflammation in the brain, caused by the disease, improve memory recovery, and lower the number of clots formed in the brain by way of the anti-amyloid properties of the secretome.

The experiment was conducted using genetically engineered male mice, which had Alzheimer’s disease, that were all raised and stored in the same conditions, along with wild-type, or typical mice, which were also raised and stored under the same conditions. The mice were divided into six different experimental groups and each group was given different treatment. There were variations in how the treatment was administered, IV injection or intranasal, and which treatment solution was given. Intranasal refers to when medication is administered via the nose. The different treatment solutions include saline, a mesenchymal stem cell secretome solution grown under typical conditions or one grown while exposed to an injured environment. This was done to show whether exposure to an injured environment was crucial for the treatment to work. Seven days following the treatment the mice completed a novel object recognition memory test to look at memory recovery.

The results from this experiment showed that a single IV injection of the mesenchymal stem cell secretome solution, which had been exposed to the injured environment, generated an increase in memory recovery for a short period of time. It was also shown to reduce brain inflammation and amyloid clots by 30% after just one dose. The secretome solution that had not been exposed to an injured environment showed no improvement. The experiment was redone with older mice that had more damage due to Alzheimer’s disease and while one dose was able to improve memory recovery for a short time it was unable to lower inflammation and clots. To improve memory for a longer period the treatment solution was injected via intranasal treatment, and this was done once per week for a month. The results showed complete memory recovery, however, it is noted that there could be alternative explanations for this phenomenon.

This experiment effectively showed that the secretome of mesenchymal stem cells can replicate the benefits of the cell without the disadvantages. It is capable of improving memory recovery, lowering brain inflammation and reducing the number of amyloid clots formed. It demonstrated the necessity of exposure to an injured environment and utilized an injured environment similar to what the cells would be attempting to correct. Additionally, it was able to highlight the benefits of continued intranasal treatment of Alzheimer’s disease.

Reference

Santamaria, G., Brandi, E., Vitola, P., Grandi, F., Ferrara, G., Pischiutta, F., . . . Balducci, C. (2020, July 23). Intranasal delivery of          mesenchymal stem cell secretome repairs the brain of alzheimer’s mice. Retrieved February 27, 2021, from                                  https://www.nature.com/articles/s41418-020-0592-2