ABSTRACT
Objective To analyze the expression of synaptophysin (SY) in hippocampal dentate gyrus of rats with hypoxic-ischemic brain damage(HIBD) after the injection of bone marrow stromal cells(BMSCs) and its supernatant into the lateral ventricle and to explore the mechanism of potential effects. Methods Eighty 7-day-old sprague-dawley(SD) rats were randomly divided into sham group, control group, cell group and supernatant group, with 20 rats in each group. The HIBD model was established via the ligation of left carotid arteries followed by 2-hour hypoxia. One week later, control group was injected with 0.01 mol/L PBS via the left ventricle. Meanwhile, cell and supernatant group were injected with BMSCs and supernatant harvested from BMSC culture, respectively, via the same route. For spam group, the left carotid arteries were separated but not ligated, and no hypoxia treatment was imposed on this group. They also received 0.01mol/L PBS injection one week post surgery. After 8 weeks, the expression of SY in the dentate gyrus of rats was measured. Results Compared with sham group, model group showed significantly lower IOD (integral optical density) of SY positive material in the dentate gyrus(P 0.05). Conclusions BMSCs and supernatant injected via the lateral cerebral ventricle can increase SY expression in the hippocampal dentate gyrus of HIBD rats and promote synapse formation. The mechanism of this effect may be related to cytokine secretion by BMSCs which promotes synapse formation.