Distribution of human umbilical cord blood-derived mesenchymal stem cells in the Alzheimer's disease transgenic mouse after a single intravenous injection.

The aim of this study was to track the migration of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) administered through a single intravenous injection and to observe the consequential therapeutic effects in a transgenic Alzheimer's disease mouse model. Ten-month-old APP/PS1 mice received a total injection of 1×10 cells through the lateral tail vein and were killed 1, 4, and 7 days after administration. On the basis of immunohistochemical analysis, hUCB-MSCs were not detected in the brain at any of the time points. Instead, most of the injected mesenchymal stem cells were found to be distributed in the lung, heart, and liver. In terms of the molecular effects, statistically significant differences in the amyloid β protein, neprilysin, and SOX2 levels were not observed among the groups. On the basis of the results from this study, we suggest that single intravenously administered hUCB-MSCs are not delivered to the brain and also do not have a significant influence on Alzheimer's disease pathology.