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. To understand the underlying mechanism, we infused amyloid β (Aβ) peptide in the lateral ventricle of adult Wister rats using 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. The results showed that Aβ infusion significantly decreased learning related behavior, whereas that was not decreased in B10 transplanted group. Nissl staining results demonstrated that hippocampal pyramidal neurons in CA1 area was decreased in Aβ-infused rats, whereas that was not decreased in B10 transplanted group. Immunohistochemical examination showed that Aβ mainly deposited in the vessels of the brains of Aβ-infused rats, which was decreased by B10 transplantation. Further analysis showed that B10 transplantation increased vessel density, as revealed by immunofluorescence staining. Moreover, the number of astrocyte and microglia was decreased by Aβ infusion, 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 cerebral vessel and increased angiogenesis, which could be possible cause of improved neurological performance in Aβ-infused rats.