Different doses of human umbilical cord mesenchymal stem cells improve learning and memory ability of dementia rats / 中国组织工程研究

ABSTRACT

BACKGROUND:To delay the onset of Alzheimer’s disease, transplantation of viable and wel-differentiated stem cel s is expected to repair neural tissue, which has been an issue of concern. OBJECTIVE:To explore the effects of different doses of human umbilical cord mesenchymal stem cel s (hUCMSCs) on learning and memory ability of Alzheimer’s disease rats. METHODS:Fifty Sprague-Dawley rats, 7 months of age, were randomized into normal, model, high-, middle-and low-dose hUCMSCs groups (n=10 per group). Rats in model and UCMSCs groups were used to make Alzheimer’s disease animals through intraperitoneal injection of 150 mg/kg D-galactose for 90 days, and rats in the normal group were given intraperitoneal injection of normal saline for 90 days. In the three hUCMSCs group, passage 3 hUCMSCs at doses of 1×105/0.2 mL/20 g, 5×105/0.2 mL/20 g, and 1×106/0.2 mL/20 g were injected via the tail vein, respectively. Forty-five days after cel transplantation, Morris water maze test was used to detect rat’s learning and memory abilities, and hematoxylin-eosin staining was used to observe pathological changes of the rat hippocampal CA1 region. RESULTS AND CONCLUSION:Compared with the normal group, the rats in the model group showed significant reduction in the ability of learning and memory. Compared with the model group, the escape latency was significantly shortened in the middle-dose hUCMSCs group (P<0.05), while the number of passing times through the platform was increased significantly (P<0.05). In the model group, the cel s in the hippocampal CA1 region were arranged irregularly with unclear nucleoli and a part of cel s were concentrated and deeply stained. In the middle-dose hUCMSCs group, the cel s in the hippocampal CA1 region were arranged regularly with clear nucleoli, and only individual cel s were stained deeply. These findings indicate that middle-dose hUCMSCs transplantation can improve the learning and memory abilities of Alzheimer’s rats.