ABSTRACT
Objective To investigate the intervention effect of CD147 on learning and memory ability in rat model of Alzheimer's disease. Methods A total of 60 healthy Sprague-Dawley rats were randomly divided into sham operation group, model group and CD147 group, 20 rats in each group. All of the rats were anesthetized with intraperitoneal injection of 10％chloral hydrate (0.3 g/kg). The rats in the model group and the CD147 group were injected with Aβ1-40 (10μg) in the bilateral hippocampal CA1 regions, while the rats in the sham operation group were injected with the same amount of saline at the same sites. After 48 h, the rats in CD147 group were injected with CD147 cDNA in the bilateral ventricles, while the rats in model group and sham operation group were injected the same amount of saline at the same sites. Morris water maze test was used to detect the ability of learning and memory of rats. The expressions ofβamyloid protein (Aβ) andγ-secretase were detected by Western blot assay. Results The escape latency was significantly longer in model group than that of sham operation group, while which was significantly lower in CD147 group than that of model group (P<0.05). The number of times across the platform and the time of staying on platform were significantly lower in model group than those of sham operation group, while which was significantly higher in the CD147 group than that of model group (P<0.05). The expressions of Aβandγ-secretase were increased significantly in model group compared to those of sham operation group, while which were significantly decreased in CD147 group compared with those of model group (P<0.05). Conclusion Exogenous CD147 can significantly improve the learning and memory ability of AD rats, and its specific mechanism may be related to regulating the activity ofγ-secretase and down regulating the expression of Aβ.
ABSTRACT
BACKGROUND:Placental mesenchymal stem cel s with rich sources are similar to bone marrow mesenchymal stem cel s in terms of morphology, surface markers and differentiation potential, which are one of ideal mesenchymal stem cel s in human body. However, there are few studies addressing the ultrastructure and phagocytotic function of human placental mesenchymal stem cel s and its physiological role in the the placenta has been little explored. OBJECTIVE:To investigate the ultrastrcture and phagocytotic function of placental mesenchymal stem cel s. METHODS:Placental mesenchymal stem cel s obtained from five placentae of normal pregnancy were cultured in vitro and observed for ultrastructure under transmission electron microscope. The fluorescent beads were added in the supernatant for 3 hours, and then the phagocytosis of placental mesenchymal stem cel s was evaluated by flow cytometry. RESULTS AND CONCLUSION:Under the transmission electron microscope, placental mesenchymal stem cel s had large nuclei with prominent nucleoli. In the cytoplasm, a plenty of rough endoplasmic reticula was seen, dilated or stacked. The cytoplasm was also rich in Golgi apparatus and lysosomes. The cel surfaces were covered by microvil i. The intercel ular junctions could be seen occasional y. A part of cel s from these five samples could phagocytose fluorescence beads, which ranged from 49.6%to 18.4%. The ultrastructural characteristics of placental mesenchymal stem cel s suggested these cel s were active to synthesize and secrete proteins and had phagocytotic function, indicating placental mesenchymal stem cel s may play a role in keeping the balance of micro-environments and clean the foreign substances in the placenta.