Evaluation of Aβ Deposits in the Hippocampus of a Rat Model of Alzheimer’s Disease After Intravenous Injection of Human Adipose Derived Stem Cells by Immuno- and Thioflavin S-Costaining

Background: Alzheimer's disease (AD) is a progressive neuropsychiatric disorder that gradually impairs memory and behavioral functions. Amyloid beta (Aβ) is considered as the most toxic substance in the brain of AD patients. Objectives: The present study was designed to evaluate Aβ deposits by Immuno- and Thioflavin S-costaining in the hippocampus of a rat model of AD after intravenous injection of human adipose-derived stem cells (hADSCs). Methods: Thirty-two male rats were included in the four groups of control, sham, AD and hADSCs. The hADSCs characterization was confirmed by the flow cytometry technique. Immuno- and Thioflavin S-costaining was utilized for detecting Aβ plaques in the hippocampus of a rat model of AD following injection of hADSCs. Results: Statistical analysis revealed that Aβ plaques increased significantly in the AD group compared to the control and sham groups. The administration of hADSCs significantly decreased immunoreactivity and Thio-S-positive plaques in the AD group. We also found that the plaques detected by anti-Aβ antibody (immunohistochemical staining) were significantly more than those distinguished by Thioflavin-S in all the groups. Conclusions: Results showed that hADSCs played an effective role in decreasing amyloids aggregation following migration to the hippocampus of the rat model of AD.