A Mesenchymal Stem Cell Line Transplantation Improves Neurological Function and Angiogenesis in Intraventricular Amyloid β-Infused Rats

Mesenchymal stem cell transplantation is demonstrated to improve neurological performance in neurodegenerative diseases including Alzheimer's disease.The objective of this study is to understand the underlying mechanism of such improvement.Amyloid β (Aβ) peptide was infused into the lateral ventricle of adult Wister rats using the osmotic pump. After 15 days of continuous infusion, a mesenchymal stem cell line (B10) was transplanted in the lateral ventricle. Learning-related behavior was evaluated by 2-way shuttle avoidance test. Fifteen days after B10 transplantation, pathological and expressional changes were evaluated.Compared to sham group, learning-related behavior was significantly decreased in Aβ-infused non-transplanted group, but not in B10-transplanted group. Nissl staining results demonstrated that the number of hippocampal pyramidal neurons in CA1 area in B10-transplanted group was similar to the sham group, whereas that was decreased in Aβ-infused non-transplanted group. Aβ mainly deposited in the vessels of the brains of Aβ-infused non-transplanted rats, which was decreased by B10 transplantation. Moreover, B10 transplantation increased vessel density as well as endoglin positive cells. The number of astrocyte and microglia was decreased in Aβ-infused non-transplanted group, which was returned to the level of sham animals by B10 transplantation. Real-time PCR and immunostaining results showed that B10 transplantation significantly increased IL-1β mRNA and protein expression.Thus, our result showed that MSC transplantation effectively decreased Aβ deposition in the cerebral vessel and increased angiogenesis, which could be a possible cause of improved neurological performance in Aβ-infused AD model rats.