Anti-inflammatory effects of bone marrow mesenchymal stem cells on mice with Alzheimer's disease.

Anti-inflammatory effects of bone marrow mesenchymal stem cells (BMSCs) on mice with Alzheimer's disease (AD) were investigated. Twenty amyloid precursor protein (APP)/presenilin-1 (PS1) double transgenic mice were randomly divided into two groups: the AD control group and the stem cell treatment group. The normal control group consisted of 10 non-transgenic mice. The stem cell treatment group was injected with BMSCs, and the two control groups were given the same volume of normal saline. The Morris water maze test was used to compare the memory function of mice, and the relative expression levels of β-site APP cleaving enzyme 1 (BACE1) and α-2-macroglobulin (A2M) genes were detected by fluorescence quantitative polymerase chain reaction (qPCR). Amyloid β (Aβ)1-42 content in brain tissues of mice and inflammatory cytokines, interleukin (IL)-1, IL-2, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were detected using enzyme-linked immunosorbent assay (ELISA). Compared with that in the AD control group, the escape latency in the water maze in the stem cell treatment group was shortened, the time of crossing the ring for the first time was decreased, but the frequency of crossing the ring was increased (P<0.05). Aβ1-42 content in the AD control group was higher than that in the stem cell treatment group and the normal control group (P<0.05). The relative expression level of BACE1 gene in the stem cell treatment group was lower than that in the AD control group (P<0.05), but that of A2M gene was increased (P<0.05). At 14 days after treatment, the contents of IL-1, IL-2, TNF-α and IFN-γ in blood in the stem cell treatment group were lower than those in the AD control group (P<0.05). Human BMSCs can ameliorate the symptoms of AD by decreasing the levels of inflammatory cytokines and regulating the expression of Aβ-related genes.