Abstract
Mesenchymal stem cells (MSCs) have the ability to phagocytize amyloid beta (Aβ) plaques and lower inflammation through the activity of microglia. Peroxisome proliferator-activated receptor gamma (PPARγ) is a protein involved in reducing inflammation through the activity of microglia and the phagocytosis of Aβ plaques by scavenger receptor CD36, in this study, the effect of MSCs therapy on memory function and plaques was investigated. A total of 24 adult male Wistar rats were randomly divided into three groups:1) the control group, 2) the Aβ-treated group (Alzheimer's disease (AD)), and 3) the MSC-treated group (AD + MSC). After the treatment with Aβ and MSCs, western blotting and real-time polymerase chain reaction (PCR) techniques were used to assess protein and gene expression levels, respectively. MSCs improved spatial learning and memory in the AD group (p ≤0.05). The expression levels of PPARγ, lncRNA TUSC7, and CD36 genes were significantly elevated in the group receiving MSCs compared to the AD group (p≤0.0001). Also, the expression level of miR-449a significantly decreased in the AD + MSC group (p≤0.0001). Moreover, western blot analysis revealed that PPARγ and CD36 protein levels were enhanced in the AD + MSC group compared to the AD group (p≤0.0001). MSC treatment led to the positive regulation of the PPARγ gene and its protein expression by ncRNAs, which could have a beneficial impact on CD36 protein levels, and subsequently, reduce the number of plaques in the cell recipient.