Protective effects of endothelial progenitor cells-derived microvesicles on hypoxic-ischemic brain damage in newborn rats / 中国新生儿科杂志

ABSTRACT

Objective To study the protective effects and preliminary mechanisms of endothelial progenitor cells-derived microvesicles (EPC-MVs) on hypoxic-ischemic brain damage (HIBD) in newborn rats by using the HIBD model.Method Rat endothelial progenitor cells (EPCs) were cultured and microvesicles were extracted from EPCs culture medium by ultracentrifugation.A total of 60 neonatal SD rats were randomly assigned into control group,HIBD group,saline group and EPC-MVs group.The HIBD model was prepared in HIBD group,saline group and EPC-MVs group.After the preparation of the HIBD model,rats in saline group and EPC-MVs group received intraventricular injection with saline and EPC-MVs,respectively.After 72 hours,the rats were sacrificed for brain tissue,cerebral infarction was detected by TTC staining,vascular endothelial growth factor (VEGF) mRNA was tested by real-time PCR,protein western blot was used to detect changes in VEGF protein expression.Result Cells extracted and cultured from the spleen of 12-week-old SD rats were confirmed as EPCs by morphology and flow cytometry.EPC-MVs isolated by high-speed centrifugation from EPCs culture supernatant met the morphological characteristics of microvesicles by transmission electron microscopy.The infarcted brain tissue was not detected in the control group.The cerebral infarction volume ratios of HIBD group,saline group and EPC-MVs group were (80.3 ± 6.3) ％,(77.9 ± 8.9) ％,(35.2 ± 7.7) ％,respectively.The infarct volume of EPC-MVs group was significantly lower than that of HIBD group and saline group (P ＜ 0.001).The expression of VEGF mRNA and protein in HIBD group,saline group and EPC-MVs group were higher than those in control group (P ＜0.001).Among them,EPC-MVs group had the most significant increase,compared with the other three experimental groups,and the difference was statistically significant (P ＜ 0.001).There was no significant difference between saline group and HIBD group in the expression of VEGF mRNA and protein (P ＞ 0.05).Conclusion Intraventricular injection of EPC-MVs can attenuate HIBD in neonatal rats,and the mechanism may be related to up-regulation of VEGF expression.