Backgrounds: The aim of this study was to track the migration of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) administered via a single intravenous injection and to observe the consequential therapeutic effects in a transgenic Alzheimer’s disease (AD) mouse model.
Methods: 10-month-old APP/PS1 mice received a total injection of 1 × 10^6 cells through the lateral tail vein and were sacrificed 1, 4, and 7 days after administration.
Results: Based upon immunohistochemical analysis, hUCB-MSCs were not detected in the brain for each time point. Instead, most of the injected MSCs were found to be distributed in the lung, heart, and liver. In terms of the molecular effects, statistically significant differences in the amyloid beta protein, Neprilysin (NEP), and SOX2 levels were not observed among the groups.
Conclusion: Our study showed that a single dose of 1X10^6 hUCB-MSCs injected intravenously into AD transgenic mice resulted in neither delivery into the brain nor generation of therapeutic benefits via paracrine activity. In order to utilize the intravenous route as an effective delivery route for AD stem cell therapy, it will be crucial to perform additional studies on how to increase the permeability of the BBB and how to decrease the entrapment of cells in organs such as the lung and liver.